Add QoS policies and minimum bandwidth rule client

The goal of the QoS policies and QoS minimum bandwidth rules client for
tempest is to make possible the end-to-end testing of the placement
based bandwidth feature.

Change-Id: I417574e3ef24e658b6cd2ce290f897180fed5300
Partial-Bug: #1578989
See-Also: https://review.openstack.org/502306 (nova spec)
See-Also: https://review.openstack.org/508149 (neutron spec)
7 files changed