Merge branch 'release/3.6' into develop
transient patch to avoid celery hostname clashes, but not so cool because it will restart all roles of a given worker, even if only one is concerned.
simplification and new feature at the same time: always add the  argument to celery workers, which allows fine-grained operations on already running celery clusters.
bump version in __init__.py
Merge branch 'release/3.6.1'