This migrates the above files from tempest. This includes tempest commits:
* volumes_client.py : Ibd9b6c67c5b9790b6d6f1a76d334ee5d6c98ad5f
* test_volumes_client.py: Ibd9b6c67c5b9790b6d6f1a76d334ee5d6c98ad5f
* volumes.py : Ica929c402a3d042ae751302384e68853eb28b405
to see the commit history for these files refer to the above Change-Ids
in the tempest repository.
Partially implements blueprint migrate-service-clients-to-tempest-lib
Change-Id: I10913f82dc3d0bef53edd67144cb47580d3c574d