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
Perhaps using an is assertion would be stronger than an equality assertion. For instance assertTrue(result.error is error_codes.PLP0004). This would also reduce the line count because if it is the same object, you know the type and all values are the same.