[volume] Add get_quotas request
[volume] Add get_default_quotas request
[volume] Add update_quotas request
Add github link for v1 cinderclient quotas code as docs
Change test description
[volume][v2] Add get_quotas request
[volume][v2] Add get_default_quotas request
[volume][v2] Add update_quotas request
Merge pull request #20 from choodur/feature/AVIATORAPI-42

[AVIATORAPI-42][volume] Quota sets