manila: Update tempest code used by CI
manila: Update tempest code used by CI

The tempest code base used by the CI is outdated. So update tempest
tests as done for the  generic driver CI in the Manila code base,
https://github.com/openstack/manila/commit/6b8319e32a94c228ff4258cf31dcd6c271350e1c?diff=unified#diff-e0705abec56bf0f83781d686e109d63eR63

Change-Id: Ide7966b44482dd13aadd5ef34a97c980e5752bfb
Closes-Bug: #1519012

stackforge/devstack-plugin-glusterfs,stackforge/devstack-plugin-glusterfs