Merge branch 'release/3.3.4' into develop
implementation of commands start and stop for celery workers
Merge pull request #1 from WillianPaiva/develop

implementation of commands start and stop for all workers type, and fix the upstart-only bug where old workers are not stopped before the new start because configuration changed.
bump version in __init__.py
Merge branch 'release/3.3.5'