Fix tests
Add error docs
Add swagger docs for bucket endpoints
Add integration tests
Fix tests
Fix err shadow
Make sure a bucket and a task belong to the same list when adding or updating a task
Add tests
Add getting users of a bucket
Fix log level when testing
Fix lint
Add migration for buckets
Cleanup/Comments/Reorganization
Add Kanban bucket handling
Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/393
