1100805 - Fixing consumer group bind and unbind and moving tasks from ta...

...sks/consumer_group.py to consumer group cud manager

https://bugzilla.redhat.com/show_bug.cgi?id=1100805
since these @patch signatures are all so similar, maybe de-duplicate them by patching in a setUp and removing the patch using tearDown. I do this pattern a lot with my test code now even though I only learned this pattern recently. See an example I wrote [here](https://github.com/pulp/kombu/blob/pulp-dep-3.0.15-with-qpid/kombu/tests/transport/test_qpid.py#L414).