Add GitLab CI
This checks that everything is formatted properly, the lock file is up-to-date, everything compiles, and tests pass. Test and test coverage information is passed to GitLab, and we have two caches to speed things up.
This checks that everything is formatted properly, the lock file is up-to-date, everything compiles, and tests pass. Test and test coverage information is passed to GitLab, and we have two caches to speed things up.