Skarmark 1115385 1115391

This PR fixes following 2 bugs - 
https://bugzilla.redhat.com/show_bug.cgi?id=1115385
https://bugzilla.redhat.com/show_bug.cgi?id=1115391

Basically, consumer group bind and unbind are merely used as group operations and are not stored on the consumer group permanently. It makes no sense to have APIs to get list or specific bindings on a consumer group. From what it looks like, when updating APIs to the new tasking system, these were copied by somebody from consumer controller by mistake, because the documentation in the code as well as the code was essentially looking for consumer bindings and not consumer group bindings. I have removed these apis and added a test to verify that GET on these URLs return 405. Also verified that there are no wrong api docs on these.