0.4.1

Added

• Support for class-based tests, by Richard Terry.
• Registering the freeze_time mark, thanks to Dima Tisnek, Craig Anderson and Richard Terry. This was in really high demand.
• Tests for Python 3.7 and 3.8.
• Tests for pytest 5.
• And a PyPI badge, thanks to Andreu Vallbona Plazas.

Removed

• Support for Python before 3.5 (including 2.7), implemented by Nicolas Delaby.
  Those versions are getting hard to test on CI.