Use cinderng module in controller.sls

Changed the way how volume types for backends are being installed.
Previously it was done by calling an external command grepping its
output. Now the cinderng module/state is used because using API
should be the most backwards compatible way to interract with Cinder.

Cinderng is switched to APIv2 from v3 because it's the most available
API version across releases.

While here, fixed the PEP8 compliance in the sources and added missing
indentity sections in some tests.

Change-Id: I6d1cd509f8e349ab15b698e3ebc1583b80065d4c
Fixes: PROD-14654
5 files changed