Test the mypy plugin on windows (#58)

*  Test the mypy plugin on windows

Fixes #57

* remove outdated comment

Author: lovasoa

setup.py

@@ -22,9 +22,7 @@
         "pytest",
         # re: pypy: typed-ast (a dependency of mypy) fails to install on pypy
         # https://github.com/python/typed_ast/issues/111
-        # re: win32: pytest-mypy-plugins depends on capturer, which isn't supported on
-        # windows
-        "pytest-mypy-plugins; implementation_name != 'pypy' and sys.platform != 'win32'",
+        "pytest-mypy-plugins>=1.2.0; implementation_name != 'pypy'",
     ],
 }
 EXTRAS_REQUIRE["dev"] = (