Ladok3

Bugfix: Add check if credentials is None


**Full Changelog**: https://github.com/dbosk/ladok3/compare/v4.4...v4.5

Complements bugfix in v4.3.

**Full Changelog**: https://github.com/dbosk/ladok3/compare/v4.3...v4.4

- Error-handles if keyring doesn't exist
- Updates keyring version to sync with `canvaslms` (due to security)
- Updates cryptography depend due to security


**Full Changelog**: https://github.com/dbosk/ladok3/compare/v4.2...v4.3

Updates dependencies due to security.

**Full Changelog**: https://github.com/dbosk/ladok3/compare/v4.1...v4.2

Improves help text of `report` command.

**Full Changelog**: https://github.com/dbosk/ladok3/compare/v4.0...v4.1

What's Changed
* Adds who participated in grading in reporting by dbosk in https://github.com/dbosk/ladok3/pull/72


**Full Changelog**: https://github.com/dbosk/ladok3/compare/v3.9...v4.0