Remove hosts in a nova aggregate before deleting the aggregate
Remove hosts in a nova aggregate before deleting the aggregate

Currently, an exception is thrown when you try to remove an
aggregate which has hosts in it. Cleanup doesn't take care of
this scenario.

Change-Id: I2f9b1b3eddb9c00ff3ece0f4467836ba47708683

yeming233/rally,openstack/rally,openstack/rally,openstack/rally,openstack/rally,yeming233/rally