Quota delete operation in cinder

This change adds the quota-delete operation to cinder.

It is adding the api and the tests, using the methods already
implemented in the db to destroy all the quotas for a specific
project.

Implements blueprint quota-delete

DocImpact

Change-Id: Ia040a20abb831c311eb13624ddecbbf0f12fdd9f
Merge "Quota delete operation in cinder"