community/py3-{celery,billiard,vine,case,amqp,pyro4,kombu,django-celery-results,flower}: move from testing
Take maintainership of:
- testing/py3-billiard
- testing/py3-vine
- testing/py3-case
- testing/py3-amqp
- testing/py3-pyro4
- testing/py3-kombu
Use gpep517 when not in use
Lint when issues occur
Move all to community