pin kombu to a known working version (from tower 3.1.4)
pin kombu to a known working version (from tower 3.1.4)

we're encountering some *really* gnarly bugs with newer version of
celery and kombu; pin to *exactly* what works in 3.1.4 to try to avoid
them, because we can't upgrade celery to 4.0 (where this bug *may* be
fixed)

see: https://github.com/ansible/ansible-tower/issues/6534
see: https://github.com/celery/celery/issues/3712
see: https://github.com/celery/kombu/pull/760

snahelou/awx,wwitzel3/awx,snahelou/awx,wwitzel3/awx,wwitzel3/awx,wwitzel3/awx,snahelou/awx,snahelou/awx