diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index 6a1c942df..3eb106895 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -4,15 +4,23 @@ on: [push, pull_request]
 
 jobs:
   Tests:
+    name: ${{ matrix.os }} / ${{ matrix.python-version }}
     runs-on: ubuntu-latest
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
-        python-version: [3.8]
+        os: [Ubuntu, MacOS, Windows]
+        python-version: [3.6, 3.7, 3.8, 3.9]
+        experimental: [false]
+        include:
+          - os: Ubuntu
+            python-version: "3.10.0-alpha - 3.10.0"
+            experimental: true
     steps:
       - uses: actions/checkout@v2
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v1
+        uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
 
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2add7486d..20c68cafb 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -9,15 +9,19 @@ jobs:
   Tests:
     name: ${{ matrix.os }} / ${{ matrix.python-version }}
     runs-on: ${{ matrix.os }}-latest
+    continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
         os: [Ubuntu, MacOS, Windows]
-        python-version: [3.6, 3.7, 3.8, 3.9, pypy3]
-        exclude:
-          - os: MacOS
-            python-version: pypy3
-          - os: Windows
+        python-version: [3.6, 3.7, 3.8, 3.9]
+        experimental: [false]
+        include:
+          - os: Ubuntu
             python-version: pypy3
+            experimental: false
+          - os: Ubuntu
+            python-version: "3.10.0-alpha - 3.10.0"
+            experimental: true
     steps:
       - uses: actions/checkout@v2
 
@@ -33,10 +37,7 @@ jobs:
 
       - name: Install poetry
         shell: bash
-        run: |
-          curl -fsS -o get-poetry.py https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py
-          python get-poetry.py --preview -y
-          echo "$HOME/.poetry/bin" >> $GITHUB_PATH
+        run: pip install poetry
 
       - name: Configure poetry
         shell: bash
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f7be580c1..a5cfd98a6 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -17,7 +17,7 @@ repos:
           )
 
   - repo: https://github.com/timothycrosley/isort
-    rev: 5.7.0
+    rev: 5.8.0
     hooks:
       - id: isort
         additional_dependencies: [toml]
diff --git a/poetry.lock b/poetry.lock
index e4fdb348c..f5970c175 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -128,14 +128,14 @@ python-versions = "*"
 
 [[package]]
 name = "identify"
-version = "2.1.1"
+version = "2.2.1"
 description = "File identification library for Python"
 category = "dev"
 optional = false
 python-versions = ">=3.6.1"
 
 [package.extras]
-license = ["editdistance"]
+license = ["editdistance-s"]
 
 [[package]]
 name = "idna"
@@ -175,9 +175,17 @@ zipp = {version = ">=0.4", markers = "python_version < \"3.8\""}
 docs = ["sphinx", "jaraco.packaging (>=8.2)", "rst.linker (>=1.9)"]
 testing = ["pytest (>=4.6)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pytest-cov", "pytest-enabler", "pytest-black (>=0.3.7)", "pytest-mypy"]
 
+[[package]]
+name = "iniconfig"
+version = "1.1.1"
+description = "iniconfig: brain-dead simple config-ini parsing"
+category = "dev"
+optional = false
+python-versions = "*"
+
 [[package]]
 name = "isort"
-version = "5.7.0"
+version = "5.8.0"
 description = "A Python utility / library to sort Python imports."
 category = "dev"
 optional = false
@@ -198,7 +206,6 @@ python-versions = "*"
 
 [package.dependencies]
 attrs = ">=17.4.0"
-importlib-metadata = {version = "*", markers = "python_version < \"3.8\""}
 pyrsistent = ">=0.14.0"
 six = ">=1.11.0"
 
@@ -206,14 +213,6 @@ six = ">=1.11.0"
 format = ["idna", "jsonpointer (>1.13)", "rfc3987", "strict-rfc3339", "webcolors"]
 format_nongpl = ["idna", "jsonpointer (>1.13)", "webcolors", "rfc3986-validator (>0.1.0)", "rfc3339-validator"]
 
-[[package]]
-name = "more-itertools"
-version = "8.7.0"
-description = "More routines for operating on iterables, beyond itertools"
-category = "dev"
-optional = false
-python-versions = ">=3.5"
-
 [[package]]
 name = "mypy-extensions"
 version = "0.4.3"
@@ -323,26 +322,25 @@ six = "*"
 
 [[package]]
 name = "pytest"
-version = "4.6.11"
+version = "6.2.2"
 description = "pytest: simple powerful testing with Python"
 category = "dev"
 optional = false
-python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,>=2.7"
+python-versions = ">=3.6"
 
 [package.dependencies]
-atomicwrites = ">=1.0"
-attrs = ">=17.4.0"
-colorama = {version = "*", markers = "sys_platform == \"win32\" and python_version != \"3.4\""}
+atomicwrites = {version = ">=1.0", markers = "sys_platform == \"win32\""}
+attrs = ">=19.2.0"
+colorama = {version = "*", markers = "sys_platform == \"win32\""}
 importlib-metadata = {version = ">=0.12", markers = "python_version < \"3.8\""}
-more-itertools = {version = ">=4.0.0", markers = "python_version > \"2.7\""}
+iniconfig = "*"
 packaging = "*"
-pluggy = ">=0.12,<1.0"
-py = ">=1.5.0"
-six = ">=1.10.0"
-wcwidth = "*"
+pluggy = ">=0.12,<1.0.0a1"
+py = ">=1.8.2"
+toml = "*"
 
 [package.extras]
-testing = ["argcomplete", "hypothesis (>=3.56)", "nose", "requests", "mock"]
+testing = ["argcomplete", "hypothesis (>=3.56)", "mock", "nose", "requests", "xmlschema"]
 
 [[package]]
 name = "pytest-cov"
@@ -361,17 +359,17 @@ testing = ["fields", "hunter", "process-tests (==2.0.2)", "six", "pytest-xdist",
 
 [[package]]
 name = "pytest-mock"
-version = "2.0.0"
-description = "Thin-wrapper around the mock package for easier use with py.test"
+version = "3.5.1"
+description = "Thin-wrapper around the mock package for easier use with pytest"
 category = "dev"
 optional = false
-python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+python-versions = ">=3.5"
 
 [package.dependencies]
-pytest = ">=2.7"
+pytest = ">=5.0"
 
 [package.extras]
-dev = ["pre-commit", "tox"]
+dev = ["pre-commit", "tox", "pytest-asyncio"]
 
 [[package]]
 name = "pyyaml"
@@ -383,7 +381,7 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*"
 
 [[package]]
 name = "regex"
-version = "2020.11.13"
+version = "2021.3.17"
 description = "Alternative regular expression module, to replace re."
 category = "dev"
 optional = false
@@ -464,16 +462,16 @@ python-versions = "*"
 
 [[package]]
 name = "urllib3"
-version = "1.26.3"
+version = "1.26.4"
 description = "HTTP library with thread-safe connection pooling, file post, and more."
 category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, <4"
 
 [package.extras]
-brotli = ["brotlipy (>=0.6.0)"]
 secure = ["pyOpenSSL (>=0.14)", "cryptography (>=1.3.4)", "idna (>=2.0.0)", "certifi", "ipaddress"]
 socks = ["PySocks (>=1.5.6,!=1.5.7,<2.0)"]
+brotli = ["brotlipy (>=0.6.0)"]
 
 [[package]]
 name = "vendoring"
@@ -496,7 +494,7 @@ test = ["pytest", "pytest-xdist", "pytest-cov", "pytest-mock"]
 
 [[package]]
 name = "virtualenv"
-version = "20.4.2"
+version = "20.4.3"
 description = "Virtual Python Environment builder"
 category = "dev"
 optional = false
@@ -514,14 +512,6 @@ six = ">=1.9.0,<2"
 docs = ["proselint (>=0.10.2)", "sphinx (>=3)", "sphinx-argparse (>=0.2.5)", "sphinx-rtd-theme (>=0.4.3)", "towncrier (>=19.9.0rc1)"]
 testing = ["coverage (>=4)", "coverage-enable-subprocess (>=1)", "flaky (>=3)", "pytest (>=4)", "pytest-env (>=0.6.2)", "pytest-freezegun (>=0.4.1)", "pytest-mock (>=2)", "pytest-randomly (>=1)", "pytest-timeout (>=1)", "packaging (>=20.0)", "xonsh (>=0.9.16)"]
 
-[[package]]
-name = "wcwidth"
-version = "0.2.5"
-description = "Measures the displayed width of unicode strings in a terminal"
-category = "dev"
-optional = false
-python-versions = "*"
-
 [[package]]
 name = "zipp"
 version = "3.4.1"
@@ -537,7 +527,7 @@ testing = ["pytest (>=4.6)", "pytest-checkdocs (>=1.2.3)", "pytest-flake8", "pyt
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.6"
-content-hash = "9a3dbd14f45aa7c96293a0b4286c71f0b6501bc5fda78d834a9212c0c55cf3cd"
+content-hash = "f454025163c37b630e04ee93ceea5ad23471dcfc38127e3d7259deac52bee0f6"
 
 [metadata.files]
 appdirs = [
@@ -643,8 +633,8 @@ filelock = [
     {file = "filelock-3.0.12.tar.gz", hash = "sha256:18d82244ee114f543149c66a6e0c14e9c4f8a1044b5cdaadd0f82159d6a6ff59"},
 ]
 identify = [
-    {file = "identify-2.1.1-py2.py3-none-any.whl", hash = "sha256:220169a38a0c977c8fef377dc808d6a3330641b5211ec7356c7bbe73cda487c7"},
-    {file = "identify-2.1.1.tar.gz", hash = "sha256:da3d757c94596c50865aae63db6ba4e2e5e3f666c3ea6a6da0cd09a8b2d34abc"},
+    {file = "identify-2.2.1-py2.py3-none-any.whl", hash = "sha256:9cc5f58996cd359b7b72f0a5917d8639de5323917e6952a3bfbf36301b576f40"},
+    {file = "identify-2.2.1.tar.gz", hash = "sha256:1cfb05b578de996677836d5a2dde14b3dffde313cf7d2b3e793a0787a36e26dd"},
 ]
 idna = [
     {file = "idna-2.10-py2.py3-none-any.whl", hash = "sha256:b97d804b1e9b523befed77c48dacec60e6dcb0b5391d57af6a65a312a90648c0"},
@@ -658,18 +648,18 @@ importlib-resources = [
     {file = "importlib_resources-5.1.2-py3-none-any.whl", hash = "sha256:ebab3efe74d83b04d6bf5cd9a17f0c5c93e60fb60f30c90f56265fce4682a469"},
     {file = "importlib_resources-5.1.2.tar.gz", hash = "sha256:642586fc4740bd1cad7690f836b3321309402b20b332529f25617ff18e8e1370"},
 ]
+iniconfig = [
+    {file = "iniconfig-1.1.1-py2.py3-none-any.whl", hash = "sha256:011e24c64b7f47f6ebd835bb12a743f2fbe9a26d4cecaa7f53bc4f35ee9da8b3"},
+    {file = "iniconfig-1.1.1.tar.gz", hash = "sha256:bc3af051d7d14b2ee5ef9969666def0cd1a000e121eaea580d4a313df4b37f32"},
+]
 isort = [
-    {file = "isort-5.7.0-py3-none-any.whl", hash = "sha256:fff4f0c04e1825522ce6949973e83110a6e907750cd92d128b0d14aaaadbffdc"},
-    {file = "isort-5.7.0.tar.gz", hash = "sha256:c729845434366216d320e936b8ad6f9d681aab72dc7cbc2d51bedc3582f3ad1e"},
+    {file = "isort-5.8.0-py3-none-any.whl", hash = "sha256:2bb1680aad211e3c9944dbce1d4ba09a989f04e238296c87fe2139faa26d655d"},
+    {file = "isort-5.8.0.tar.gz", hash = "sha256:0a943902919f65c5684ac4e0154b1ad4fac6dcaa5d9f3426b732f1c8b5419be6"},
 ]
 jsonschema = [
     {file = "jsonschema-3.2.0-py2.py3-none-any.whl", hash = "sha256:4e5b3cf8216f577bee9ce139cbe72eca3ea4f292ec60928ff24758ce626cd163"},
     {file = "jsonschema-3.2.0.tar.gz", hash = "sha256:c8a85b28d377cc7737e46e2d9f2b4f44ee3c0e1deac6bf46ddefc7187d30797a"},
 ]
-more-itertools = [
-    {file = "more-itertools-8.7.0.tar.gz", hash = "sha256:c5d6da9ca3ff65220c3bfd2a8db06d698f05d4d2b9be57e1deb2be5a45019713"},
-    {file = "more_itertools-8.7.0-py3-none-any.whl", hash = "sha256:5652a9ac72209ed7df8d9c15daf4e1aa0e3d2ccd3c87f8265a0673cd9cbc9ced"},
-]
 mypy-extensions = [
     {file = "mypy_extensions-0.4.3-py2.py3-none-any.whl", hash = "sha256:090fedd75945a69ae91ce1303b5824f428daf5a028d2f6ab8a299250a846f15d"},
     {file = "mypy_extensions-0.4.3.tar.gz", hash = "sha256:2d82818f5bb3e369420cb3c4060a7970edba416647068eb4c5343488a6c604a8"},
@@ -710,16 +700,16 @@ pyrsistent = [
     {file = "pyrsistent-0.16.1.tar.gz", hash = "sha256:aa2ae1c2e496f4d6777f869ea5de7166a8ccb9c2e06ebcf6c7ff1b670c98c5ef"},
 ]
 pytest = [
-    {file = "pytest-4.6.11-py2.py3-none-any.whl", hash = "sha256:a00a7d79cbbdfa9d21e7d0298392a8dd4123316bfac545075e6f8f24c94d8c97"},
-    {file = "pytest-4.6.11.tar.gz", hash = "sha256:50fa82392f2120cc3ec2ca0a75ee615be4c479e66669789771f1758332be4353"},
+    {file = "pytest-6.2.2-py3-none-any.whl", hash = "sha256:b574b57423e818210672e07ca1fa90aaf194a4f63f3ab909a2c67ebb22913839"},
+    {file = "pytest-6.2.2.tar.gz", hash = "sha256:9d1edf9e7d0b84d72ea3dbcdfd22b35fb543a5e8f2a60092dd578936bf63d7f9"},
 ]
 pytest-cov = [
     {file = "pytest-cov-2.11.1.tar.gz", hash = "sha256:359952d9d39b9f822d9d29324483e7ba04a3a17dd7d05aa6beb7ea01e359e5f7"},
     {file = "pytest_cov-2.11.1-py2.py3-none-any.whl", hash = "sha256:bdb9fdb0b85a7cc825269a4c56b48ccaa5c7e365054b6038772c32ddcdc969da"},
 ]
 pytest-mock = [
-    {file = "pytest-mock-2.0.0.tar.gz", hash = "sha256:b35eb281e93aafed138db25c8772b95d3756108b601947f89af503f8c629413f"},
-    {file = "pytest_mock-2.0.0-py2.py3-none-any.whl", hash = "sha256:cb67402d87d5f53c579263d37971a164743dc33c159dfb4fb4a86f37c5552307"},
+    {file = "pytest-mock-3.5.1.tar.gz", hash = "sha256:a1e2aba6af9560d313c642dae7e00a2a12b022b80301d9d7fc8ec6858e1dd9fc"},
+    {file = "pytest_mock-3.5.1-py3-none-any.whl", hash = "sha256:379b391cfad22422ea2e252bdfc008edd08509029bcde3c25b2c0bd741e0424e"},
 ]
 pyyaml = [
     {file = "PyYAML-5.4.1-cp27-cp27m-macosx_10_9_x86_64.whl", hash = "sha256:3b2b1824fe7112845700f815ff6a489360226a5609b96ec2190a45e62a9fc922"},
@@ -745,47 +735,47 @@ pyyaml = [
     {file = "PyYAML-5.4.1.tar.gz", hash = "sha256:607774cbba28732bfa802b54baa7484215f530991055bb562efbed5b2f20a45e"},
 ]
 regex = [
-    {file = "regex-2020.11.13-cp36-cp36m-macosx_10_9_x86_64.whl", hash = "sha256:8b882a78c320478b12ff024e81dc7d43c1462aa4a3341c754ee65d857a521f85"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux1_i686.whl", hash = "sha256:a63f1a07932c9686d2d416fb295ec2c01ab246e89b4d58e5fa468089cab44b70"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:6e4b08c6f8daca7d8f07c8d24e4331ae7953333dbd09c648ed6ebd24db5a10ee"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux2010_i686.whl", hash = "sha256:bba349276b126947b014e50ab3316c027cac1495992f10e5682dc677b3dfa0c5"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux2010_x86_64.whl", hash = "sha256:56e01daca75eae420bce184edd8bb341c8eebb19dd3bce7266332258f9fb9dd7"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux2014_aarch64.whl", hash = "sha256:6a8ce43923c518c24a2579fda49f093f1397dad5d18346211e46f134fc624e31"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux2014_i686.whl", hash = "sha256:1ab79fcb02b930de09c76d024d279686ec5d532eb814fd0ed1e0051eb8bd2daa"},
-    {file = "regex-2020.11.13-cp36-cp36m-manylinux2014_x86_64.whl", hash = "sha256:9801c4c1d9ae6a70aeb2128e5b4b68c45d4f0af0d1535500884d644fa9b768c6"},
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+    {file = "regex-2021.3.17-cp37-cp37m-manylinux2014_aarch64.whl", hash = "sha256:18e25e0afe1cf0f62781a150c1454b2113785401ba285c745acf10c8ca8917df"},
+    {file = "regex-2021.3.17-cp37-cp37m-manylinux2014_i686.whl", hash = "sha256:a2ee026f4156789df8644d23ef423e6194fad0bc53575534101bb1de5d67e8ce"},
+    {file = "regex-2021.3.17-cp37-cp37m-manylinux2014_x86_64.whl", hash = "sha256:4c0788010a93ace8a174d73e7c6c9d3e6e3b7ad99a453c8ee8c975ddd9965643"},
+    {file = "regex-2021.3.17-cp37-cp37m-win32.whl", hash = "sha256:575a832e09d237ae5fedb825a7a5bc6a116090dd57d6417d4f3b75121c73e3be"},
+    {file = "regex-2021.3.17-cp37-cp37m-win_amd64.whl", hash = "sha256:8e65e3e4c6feadf6770e2ad89ad3deb524bcb03d8dc679f381d0568c024e0deb"},
+    {file = "regex-2021.3.17-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:a0df9a0ad2aad49ea3c7f65edd2ffb3d5c59589b85992a6006354f6fb109bb18"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux1_i686.whl", hash = "sha256:b98bc9db003f1079caf07b610377ed1ac2e2c11acc2bea4892e28cc5b509d8d5"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:808404898e9a765e4058bf3d7607d0629000e0a14a6782ccbb089296b76fa8fe"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux2010_i686.whl", hash = "sha256:5770a51180d85ea468234bc7987f5597803a4c3d7463e7323322fe4a1b181578"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux2010_x86_64.whl", hash = "sha256:976a54d44fd043d958a69b18705a910a8376196c6b6ee5f2596ffc11bff4420d"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux2014_aarch64.whl", hash = "sha256:63f3ca8451e5ff7133ffbec9eda641aeab2001be1a01878990f6c87e3c44b9d5"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux2014_i686.whl", hash = "sha256:bcd945175c29a672f13fce13a11893556cd440e37c1b643d6eeab1988c8b209c"},
+    {file = "regex-2021.3.17-cp38-cp38-manylinux2014_x86_64.whl", hash = "sha256:3d9356add82cff75413bec360c1eca3e58db4a9f5dafa1f19650958a81e3249d"},
+    {file = "regex-2021.3.17-cp38-cp38-win32.whl", hash = "sha256:f5d0c921c99297354cecc5a416ee4280bd3f20fd81b9fb671ca6be71499c3fdf"},
+    {file = "regex-2021.3.17-cp38-cp38-win_amd64.whl", hash = "sha256:14de88eda0976020528efc92d0a1f8830e2fb0de2ae6005a6fc4e062553031fa"},
+    {file = "regex-2021.3.17-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:4c2e364491406b7888c2ad4428245fc56c327e34a5dfe58fd40df272b3c3dab3"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux1_i686.whl", hash = "sha256:8bd4f91f3fb1c9b1380d6894bd5b4a519409135bec14c0c80151e58394a4e88a"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux1_x86_64.whl", hash = "sha256:882f53afe31ef0425b405a3f601c0009b44206ea7f55ee1c606aad3cc213a52c"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux2010_i686.whl", hash = "sha256:07ef35301b4484bce843831e7039a84e19d8d33b3f8b2f9aab86c376813d0139"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux2010_x86_64.whl", hash = "sha256:360a01b5fa2ad35b3113ae0c07fb544ad180603fa3b1f074f52d98c1096fa15e"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux2014_aarch64.whl", hash = "sha256:709f65bb2fa9825f09892617d01246002097f8f9b6dde8d1bb4083cf554701ba"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux2014_i686.whl", hash = "sha256:c66221e947d7207457f8b6f42b12f613b09efa9669f65a587a2a71f6a0e4d106"},
+    {file = "regex-2021.3.17-cp39-cp39-manylinux2014_x86_64.whl", hash = "sha256:c782da0e45aff131f0bed6e66fbcfa589ff2862fc719b83a88640daa01a5aff7"},
+    {file = "regex-2021.3.17-cp39-cp39-win32.whl", hash = "sha256:dc9963aacb7da5177e40874585d7407c0f93fb9d7518ec58b86e562f633f36cd"},
+    {file = "regex-2021.3.17-cp39-cp39-win_amd64.whl", hash = "sha256:a0d04128e005142260de3733591ddf476e4902c0c23c1af237d9acf3c96e1b38"},
+    {file = "regex-2021.3.17.tar.gz", hash = "sha256:4b8a1fb724904139149a43e172850f35aa6ea97fb0545244dc0b805e0154ed68"},
 ]
 requests = [
     {file = "requests-2.25.1-py2.py3-none-any.whl", hash = "sha256:c210084e36a42ae6b9219e00e48287def368a26d03a048ddad7bfee44f75871e"},
@@ -841,20 +831,16 @@ typing-extensions = [
     {file = "typing_extensions-3.7.4.3.tar.gz", hash = "sha256:99d4073b617d30288f569d3f13d2bd7548c3a7e4c8de87db09a9d29bb3a4a60c"},
 ]
 urllib3 = [
-    {file = "urllib3-1.26.3-py2.py3-none-any.whl", hash = "sha256:1b465e494e3e0d8939b50680403e3aedaa2bc434b7d5af64dfd3c958d7f5ae80"},
-    {file = "urllib3-1.26.3.tar.gz", hash = "sha256:de3eedaad74a2683334e282005cd8d7f22f4d55fa690a2a1020a416cb0a47e73"},
+    {file = "urllib3-1.26.4-py2.py3-none-any.whl", hash = "sha256:2f4da4594db7e1e110a944bb1b551fdf4e6c136ad42e4234131391e21eb5b0df"},
+    {file = "urllib3-1.26.4.tar.gz", hash = "sha256:e7b021f7241115872f92f43c6508082facffbd1c048e3c6e2bb9c2a157e28937"},
 ]
 vendoring = [
     {file = "vendoring-0.3.3-py2.py3-none-any.whl", hash = "sha256:2b91c302116320f903fdb5e60c2b0805d807e2b87425ab0c86624028aa5ffa57"},
     {file = "vendoring-0.3.3.tar.gz", hash = "sha256:2bbfc0c8da2863f4638c854b91e80c5d0ca57db62fb979d4b0f52088eeab1162"},
 ]
 virtualenv = [
-    {file = "virtualenv-20.4.2-py2.py3-none-any.whl", hash = "sha256:2be72df684b74df0ea47679a7df93fd0e04e72520022c57b479d8f881485dbe3"},
-    {file = "virtualenv-20.4.2.tar.gz", hash = "sha256:147b43894e51dd6bba882cf9c282447f780e2251cd35172403745fc381a0a80d"},
-]
-wcwidth = [
-    {file = "wcwidth-0.2.5-py2.py3-none-any.whl", hash = "sha256:beb4802a9cebb9144e99086eff703a642a13d6a0052920003a230f3294bbe784"},
-    {file = "wcwidth-0.2.5.tar.gz", hash = "sha256:c4d647b99872929fdb7bdcaa4fbe7f01413ed3d98077df798530e5b04f116c83"},
+    {file = "virtualenv-20.4.3-py2.py3-none-any.whl", hash = "sha256:83f95875d382c7abafe06bd2a4cdd1b363e1bb77e02f155ebe8ac082a916b37c"},
+    {file = "virtualenv-20.4.3.tar.gz", hash = "sha256:49ec4eb4c224c6f7dd81bb6d0a28a09ecae5894f4e593c89b0db0885f565a107"},
 ]
 zipp = [
     {file = "zipp-3.4.1-py3-none-any.whl", hash = "sha256:51cb66cc54621609dd593d1787f286ee42a5c0adbb4b29abea5a63edc3e03098"},
diff --git a/poetry/core/packages/package.py b/poetry/core/packages/package.py
index 01aa8fbbd..1662071f1 100644
--- a/poetry/core/packages/package.py
+++ b/poetry/core/packages/package.py
@@ -38,6 +38,7 @@ class Package(PackageSpecification):
         "3.7",
         "3.8",
         "3.9",
+        "3.10",
     }
 
     def __init__(
@@ -270,24 +271,45 @@ def all_classifiers(self) -> List[str]:
         else:
             python_constraint = self.python_constraint
 
-        for version in sorted(self.AVAILABLE_PYTHONS):
+        python_classifier_prefix = "Programming Language :: Python"
+        python_classifiers = []
+
+        # we sort python versions by sorting an int tuple of (major, minor) version
+        # to ensure we sort 3.10 after 3.9
+        for version in sorted(
+            self.AVAILABLE_PYTHONS, key=lambda x: tuple(map(int, x.split(".")))
+        ):
             if len(version) == 1:
                 constraint = parse_constraint(version + ".*")
             else:
                 constraint = Version.parse(version)
 
             if python_constraint.allows_any(constraint):
-                classifiers.append(
-                    "Programming Language :: Python :: {}".format(version)
-                )
+                classifier = "{} :: {}".format(python_classifier_prefix, version)
+                if classifier not in python_classifiers:
+                    python_classifiers.append(classifier)
 
         # Automatically set license classifiers
         if self.license:
             classifiers.append(self.license.classifier)
 
-        classifiers = set(classifiers)
-
-        return sorted(classifiers)
+        # Sort classifiers and insert python classifiers at the right location. We do
+        # it like this so that 3.10 is sorted after 3.9.
+        sorted_classifiers = []
+        python_classifiers_inserted = False
+        for classifier in sorted(set(classifiers)):
+            if (
+                not python_classifiers_inserted
+                and classifier > python_classifier_prefix
+            ):
+                sorted_classifiers.extend(python_classifiers)
+                python_classifiers_inserted = True
+            sorted_classifiers.append(classifier)
+
+        if not python_classifiers_inserted:
+            sorted_classifiers.extend(python_classifiers)
+
+        return sorted_classifiers
 
     @property
     def urls(self) -> Dict[str, str]:
diff --git a/poetry/core/version/helpers.py b/poetry/core/version/helpers.py
index df64b8e0f..b3f801e0a 100644
--- a/poetry/core/version/helpers.py
+++ b/poetry/core/version/helpers.py
@@ -21,6 +21,7 @@
     "3.7.*",
     "3.8.*",
     "3.9.*",
+    "3.10.*",
 ]
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 45256ad1c..8095d9d97 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,14 +39,14 @@ dataclasses = {version = "^0.8", python = "~3.6"}
 [tool.poetry.dev-dependencies]
 pre-commit = {version = "^2.10.0", python = "^3.6.1"}
 pyrsistent = "^0.16.0"
-pytest = "^4.6"
+pytest = "^6.2"
 pytest-cov = "^2.8"
-pytest-mock = "^2.0"
+pytest-mock = "^3.5"
 tox = "^3.0"
 vendoring = {version = "^0.3", python = "^3.8"}
 pep517 = "^0.8.2"
 black = {version = "^20.8b1", markers = "python_version >= '3.6' and python_version < '4.0' and implementation_name != 'pypy'"}
-isort = "^5.7.0"
+isort = "^5.8.0"
 
 [tool.black]
 line-length = 88
diff --git a/tests/masonry/builders/test_builder.py b/tests/masonry/builders/test_builder.py
index 86cf4bad5..c178ea6b8 100644
--- a/tests/masonry/builders/test_builder.py
+++ b/tests/masonry/builders/test_builder.py
@@ -92,6 +92,7 @@ def test_get_metadata_content():
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         "Topic :: Software Development :: Build Tools",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ]
diff --git a/tests/masonry/builders/test_complete.py b/tests/masonry/builders/test_complete.py
index 01a8c114a..8d7e647ee 100644
--- a/tests/masonry/builders/test_complete.py
+++ b/tests/masonry/builders/test_complete.py
@@ -272,6 +272,7 @@ def test_complete():
 Classifier: Programming Language :: Python :: 3.7
 Classifier: Programming Language :: Python :: 3.8
 Classifier: Programming Language :: Python :: 3.9
+Classifier: Programming Language :: Python :: 3.10
 Classifier: Topic :: Software Development :: Build Tools
 Classifier: Topic :: Software Development :: Libraries :: Python Modules
 Provides-Extra: time
@@ -375,6 +376,7 @@ def test_complete_no_vcs():
 Classifier: Programming Language :: Python :: 3.7
 Classifier: Programming Language :: Python :: 3.8
 Classifier: Programming Language :: Python :: 3.9
+Classifier: Programming Language :: Python :: 3.10
 Classifier: Topic :: Software Development :: Build Tools
 Classifier: Topic :: Software Development :: Libraries :: Python Modules
 Provides-Extra: time
diff --git a/tests/masonry/test_api.py b/tests/masonry/test_api.py
index a649a197c..e0c73ab4c 100644
--- a/tests/masonry/test_api.py
+++ b/tests/masonry/test_api.py
@@ -164,6 +164,7 @@ def test_prepare_metadata_for_build_wheel():
 Classifier: Programming Language :: Python :: 3.7
 Classifier: Programming Language :: Python :: 3.8
 Classifier: Programming Language :: Python :: 3.9
+Classifier: Programming Language :: Python :: 3.10
 Classifier: Topic :: Software Development :: Build Tools
 Classifier: Topic :: Software Development :: Libraries :: Python Modules
 Provides-Extra: time
diff --git a/tests/test_factory.py b/tests/test_factory.py
index da0329429..20ac95e39 100644
--- a/tests/test_factory.py
+++ b/tests/test_factory.py
@@ -117,6 +117,7 @@ def test_create_poetry():
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         "Topic :: Software Development :: Build Tools",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ]
diff --git a/tests/testutils.py b/tests/testutils.py
index 193b95cb6..4b335e790 100644
--- a/tests/testutils.py
+++ b/tests/testutils.py
@@ -12,6 +12,7 @@
 from typing import Optional
 
 from poetry.core.toml import TOMLFile
+from poetry.core.utils._compat import PY37
 
 
 try:
@@ -60,8 +61,9 @@ def subprocess_run(*args, **kwargs):  # type: (str, Any) -> subprocess.Completed
     """
     Helper method to run a subprocess. Asserts for success.
     """
+    compat_kwargs = {"text" if PY37 else "universal_newlines": True}
     result = subprocess.run(
-        args, text=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, **kwargs
+        args, **compat_kwargs, stdout=subprocess.PIPE, stderr=subprocess.PIPE, **kwargs
     )
     assert result.returncode == 0
     return result