get_type_hints() fails on FuncFixtureInfo.__init__

[Vlad-Shcherbina]

This is pretty much the same issue as #3635.

To reproduce, run the following:

import typing
import _pytest.fixtures
print(typing.get_type_hints(_pytest.fixtures.FuncFixtureInfo.__init__))

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python37\lib\typing.py", line 1001, in get_type_hints
    value = _eval_type(value, globalns, localns)
  File "C:\Python37\lib\typing.py", line 260, in _eval_type
    return t._evaluate(globalns, localns)
  File "C:\Python37\lib\typing.py", line 464, in _evaluate
    eval(self.__forward_code__, globalns, localns),
  File "<string>", line 1, in <module>
NameError: name 'List' is not defined

This happens because of these type annotations:

pytest/src/_pytest/fixtures.py

Lines 303 to 311 in 7d4c4c6

	class FuncFixtureInfo(object):
	# original function argument names
	argnames = attr.ib(type=tuple)
	# argnames that function immediately requires. These include argnames +
	# fixture names specified via usefixtures and via autouse=True in fixture
	# definitions.
	initialnames = attr.ib(type=tuple)
	names_closure = attr.ib(type="List[str]")
	name2fixturedefs = attr.ib(type="List[str, List[FixtureDef]]")

---

Version info:

• Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 27 2018, 04:59:51) [MSC v.1914 64 bit (AMD64)] on win32
• Both pytest 3.7.1 and pytest 3.7.2.dev41+g7d4c4c66