Use Cinder API V2 if V1 is disabled

Cinder API v1 will be removed in Mitaka. We should be able to run tests against APIv2 only.

Change-Id: I6916eb3e4b7c85f37be8b365b11ca8b48f88177c
Closes-Bug: #1479157
Related-Bug: #1467589
5 files changed