In order to allow clusters to be all on the same hypervisor
(affinity) or all on different hypervisors (anti-affinity) a new
argument (locality) needed to be added to the Trove cluster-create API.
This changeset addresses the Trove server part of this feature.
'locality' can now be added to the ReST payload for a cluster-create
command and it is passed along as a scheduler hint to Nova.
The cluster scenario tests were enhanced to test that 'affinity'
works. Testing that 'anti-affinity' fails proved to be too
time consuming, since at present the only way for a cluster to
'fail' is to timeout (and that takes 10 hours).
The server-group is checked to make sure it is created properly,
and that it has been deleted after all the related instances are gone.
DocImpact: New functionality
Partially implements: blueprint replication-cluster-locality
Depends-On: Ie46cfa69ffe6a64760aca38c495563f5724bd0d0
Change-Id: I657bf5c023d0257e462cc39f57c16eb6ee83807a
51f2655770