Fix gate-tempest-dsvm orchestration.stacks.test_volumes failure

Change api tests to use cinder v2 api with devstack.
Cinder v1 API is depricated and disabled[1] by default
with devstack now.

[1]http://docs.openstack.org/developer/devstack/configuration.html
Co-Authored-By: Sirushti Murugesan <sirushti.murugesan@hp.com>
Change-Id: I5c4485a0f1d89a63548b627502be99ce30c0f00b
Closes-Bug: #1500780
2 files changed