Pytest-mypy-plugins

Features

- Adds `--mypy-only-local-stub` CLI flag to ignore errors in site-packages

Bugfixes

- Changes how `MYPYPATH` and `PYTHONPATH` are calcualted. We now expand `$PWD` variable and also include relative paths specified in `env:` section

Features

- Adds `python3.9` support
- Bumps required version of `pytest` to `>=6.0`
- Bumps required version of `mypy` to `>=0.790`

Misc

- Moves from Travis to Github Actions

Features

- Adds `PYTHONPATH` and `MYPYPATH` special handling

- Adds `parametrized` option
- Fixes deprecation warnings for `pytest`
- Bumps minimal `pytest` version to `5.4`