Updated openstack/openstack
Project: openstack/tempest  e7eed18202c965197843fad81b63eb2ea012b1c9
null
Fix class inheritance for volume_types tests

Previously the tests in test_volume_types.py manually setup an
admin_client using the admin credentials specified in the config file.
However, this is not correct because with tenant isolation those
credentials shouldn't be used other then to create a new tenant.
Additionally, everything performed in the test class's setUpClass was
already done in the base class. This commit corrects this by
changing the test class inheritance to the proper base class.

Closes-Bug: #1271312

Change-Id: Ia798c2c41d132a2ed17d6e0a9215d21a00c97a32