Add celery to requirements.txt
Celery related settings
Bump version to 0.4
Create celery app object.
Move result storing logic to models.
Remove old workers code.
Enqueue jobs to celery.
Update controllers to use new Job class.
Deprecate old runworkers command.
Remove the data.Manager as it's not needed anymore.
Remove tests for old Job class.
Fix test due to refactor.
Move outdated queries selection logic to model.
Update .gitignore.
Schedule refresh_queries using celery_beat.
Remove unused dependencies.
Use cls instead of explicit class name
Add queue name to data source
Use data source's queue name.
Update tests