Remove old driver mappings from Havana

These were deprecated in Havana and don't need to be in Juno.

Change-Id: I5ff537cc08f38f16f3d36a8a3714c025266f67fb
Fallback to None on missing Glance image attrs

It's possible for glance images to be missing attributes like name and
checksum. We'll just set those to None by default to avoid missing key
exceptions being raised.

Closes-Bug: #1308058
Change-Id: I85c42f8351763da201021a22f5ff0ebd62c6b2db
Fix bad indentation in tests

Remove a number of bad indentation errors flagged
by pylint.

Change-Id: I0a048d96aba09b2f14360ceffb1fe167fb613674
Keep volume available if retype fails due to quota

If we're over quota for a volume type that we're retyping a volume to,
keep the volume available.

Closes-Bug: #1308819
Change-Id: I7e66e95bf12b7e5a6df04eeb5a501badb5f2941f
Merge "Fix bad indentation in tests"
Merge "Fallback to None on missing Glance image attrs"
Merge "Remove old driver mappings from Havana"
Merge "Keep volume available if retype fails due to quota"