Changes:
- Skip support for Python 3.7
- Update validate geojson (#680).
- Sanitize test suite (#684, #683, #682, #681).
- Support Python3.10/3.11, documentation fixes, and general codebase cleanup (#677).
- Extended env variable interpolation (#675)
- Don't use deprecated distutils module (#672).
- Fixed tox.ini parameter passenv (#670).
- Improve the implementation of pywps.inout.literaltypes (#668).
- Fix tests/test_capabilities.py with correct check of request case (#665).
- Activate async test (#664).
- Move Sleep process definition (#663).
- Remove use of mutable as default value in Process.init (#660).
- Better handle of crashed processes (#659).
- Change coveralls branch from master to main (#655).