Enable cinder v2 api tests in volume quotas

To run cinder v2 volume quotas and volume quotas negative test,
volume_quotas_v2_client is added in services side.
We are not including xml coverage for the respective test.

Partially implements: blueprint cinder-v2-api-tests

Change-Id: Icad4d24d99d3a4f7ab6008db35fab1dfd13784e9
diff --git a/tempest/clients.py b/tempest/clients.py
index 486eef2..5873a85 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -138,6 +138,8 @@
 from tempest.services.volume.json.volumes_client import VolumesClientJSON
 from tempest.services.volume.v2.json.admin.volume_hosts_client import \
     VolumeHostsV2ClientJSON
+from tempest.services.volume.v2.json.admin.volume_quotas_client import \
+    VolumeQuotasV2Client
 from tempest.services.volume.v2.json.admin.volume_types_client import \
     VolumeTypesV2ClientJSON
 from tempest.services.volume.v2.json.availability_zone_client import \
@@ -302,6 +304,7 @@
         self.volume_hosts_v2_client = VolumeHostsV2ClientJSON(
             self.auth_provider)
         self.volume_quotas_client = VolumeQuotasClientJSON(self.auth_provider)
+        self.volume_quotas_v2_client = VolumeQuotasV2Client(self.auth_provider)
         self.volumes_extension_client = VolumeExtensionClientJSON(
             self.auth_provider)
         self.volumes_v2_extension_client = VolumeV2ExtensionClientJSON(