Add cloud quota models in automate
Add virtual column used to CloudResourceQuota.

So the column used will be exposed to automate automatically and available for reporting.

https://bugzilla.redhat.com/show_bug.cgi?id=1142475
Add test cases for exposing OpenstackResourceQuota and related models to automate.

https://bugzilla.redhat.com/show_bug.cgi?id=1142475
Merge pull request #664 from lfu/b1142475-automate-models-for-quota

Expose OpenstackResourceQuota and related models to automate.