Mutatest Versions Save

See: https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#310

https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#302

https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#301

This is the stable release:

• https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#300

• Support for using setup.cfg for config entries like mutatest.ini as an alternate source file.
• https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#220

• Discovered the mock coverage files were UNIX-specific paths, updated testing structure for filters specifically to use os-agnostic mocks and to allow optional relative vs. full resolution of the file passed in the coverage filter.
• https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#213

• Configured tests directory to be part of the package distribution:
• https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#212
• https://docs.pytest.org/en/latest/goodpractices.html#tests-as-part-of-application-code

• Added a specific test environment for coverage v4 since v5 is the new default. This includes proper mocks of the .coverage file in both JSON and SQL form.

https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#211

Coverage 5.0.0 moved to a SQLite database format. This release supports both 4.4x and 5.x versions of coverage.

https://github.com/EvanKepner/mutatest/blob/master/CHANGELOG.rst#210

RTD builds were incomplete due to missing typing-extension, this is now explicit in setup.py and docs/requirements.txt for potential Python 3.7 import errors.