Using doubles quote since Black refers double quotes

Author: Pierre-Luc Tessier Gagné

setup.py

@@ -93,7 +93,7 @@
         "wrapt~=1.10",
         "aenum",
         'windows-curses;platform_system=="Windows"',
-        'filelock'
+        "filelock",
     ],
     setup_requires=["pytest-runner"],
     extras_require=extras_require,