This pytest plugin produces coverage reports. Compared to just
using coverage run this plugin does some extras:

- Subprocess support: you can fork or run stuff in a subprocess
  and will get covered without any fuss.
- Xdist support: you can use all of pytest-xdist’s features and
  still get coverage.
- Consistent pytest behavior. If you run coverage run -m pytest you
  will have slightly different sys.path (CWD will be in it, unlike
  when running pytest).

All features offered by the coverage package should work, either
through pytest-cov’s command line options or through coverage’s
config file.
