Bugfixes
* 0d2872f Fix crash on duplicated grade spec in single repo (23)
Documentation
* 71270f8 Update build status badge in README
* ca56edc Update docs on configuration, fix 20 fix 21
* eaace47 Fix badges in README
Other
* 8f7bb46 Add deploy action
* dd05ea8 Add missing "on" to workflow
* 603bdec Migrate CI to GitHub Actions