Compatibilty check fails with aiohttp-3.7.4.post0

[federicober]

Hello!

The compatibility check fails when there is a post release tag, as it is the case for the latest version of aiohttp.

I can happily submit a PR to fix this!

aioresponses==0.6.4

Traceback:

ImportError while loading conftest 'tests/unit/conftest.py'.
tests/unit/conftest.py:10: in <module>
    import aioresponses
venv/lib/python3.6/site-packages/aioresponses/__init__.py:2: in <module>
    from .core import CallbackResult, aioresponses
venv/lib/python3.6/site-packages/aioresponses/core.py:21: in <module>
    from .compat import (
venv/lib/python3.6/site-packages/aioresponses/compat.py:17: in <module>
    AIOHTTP_VERSION = StrictVersion(aiohttp_version)
../../../.pyenv/versions/3.6.10/lib/python3.6/distutils/version.py:40: in __init__
    self.parse(vstring)
../../../.pyenv/versions/3.6.10/lib/python3.6/distutils/version.py:137: in parse
    raise ValueError("invalid version number '%s'" % vstring)
E   ValueError: invalid version number '3.7.4.post0'

[federicober]

Sorry, there was a problem with the my PyPI mirror impeding me to get the latest version of the package. Indeed this has been fixed.