Fix Cluster-Create and Cluster-Show Response
Fix Cluster-Create and Cluster-Show Response

the refactoring in Ie1ac42d61e920ac8ea1ebab35c2db096fd313077
broke the responses for the aforementioned commands,
resulting in stacktraces.

Change-Id: Idb6d5677cb854b9dc76ad621910277b687c111a1
Closes-Bug: #1368982

Tesora/tesora-python-troveclient,openstack/python-troveclient,openstack/python-troveclient,Tesora/tesora-python-troveclient