-------------
- Use faulthandler when testing and fix discovered errors (115, 117).
- Fix support for None username in credentials to be consistent in all backends (99).
- Test also on cp38, cp39, cp310, cp311 and use cp38 for linking (114, 107, 100).
- Add support for CredEnumerate extending code from markb-EE (110, 109, 111)
- Remove support for older python versions < cp36 (104, 120).