Canvaslms

Fixes bug that the `login` command stores hostname in "hostname" entry of the keyring, but the credential loading is looking for it in "host". Now the loader also looks for it in the "hostname" entry of the keyring.

Improves handling of missing `login_id` attributes for students.

**Full Changelog**: https://github.com/dbosk/canvaslms/compare/v2.7...v2.8

Improves the login command and error handling for config.

**Full Changelog**: https://github.com/dbosk/canvaslms/compare/v2.6...v2.7

Adds better grade summary modules, see `pydoc3 canvaslms.grades`.

**Full Changelog**: https://github.com/dbosk/canvaslms/compare/v2.5...v2.6

Improves syntax highlighting of submission files.

**Full Changelog**: https://github.com/dbosk/canvaslms/compare/v2.4...v2.5

Adds rich to output of assignment command too (same as for the submission
command).

**Full Changelog**: https://github.com/dbosk/canvaslms/compare/v2.3...v2.4