Add client support in Cinder for volume replication

Provide Cinder client support to manage volume replication.
Cinder-specs available at https://review.openstack.org/#/c/98308/

Change-Id: Id60bacbcc113d42730e822b29b2fa78be94d3276
Implements: blueprint volume-replication
Merge "Add client support in Cinder for volume replication"