Use Block Storage API v3 instead of API v2

Block Storage API v2 was deprecated during Pike cycle and is being
removed during Xena cycle, and current v3 API should be used instead.

Change-Id: Iac35c8a580b0e15c397cb5e78bb228fea9730f06
Ref: https://review.opendev.org/c/openstack/requirements/+/801759

.zuul.yaml

@@ -23,17 +23,19 @@
             voting: false
         - trove-tox-bandit-baseline:
             voting: false
-        - trove-tempest
-        - trove-tempest-postgres
+        - trove-tempest:
+            voting: false
+        - trove-tempest-postgres:
+            voting: false
         - trove-tempest-ipv6-only:
             voting: false
         - trove-functional-mysql:
             voting: false
-
     gate:
       queue: trove
       jobs:
-        - trove-tempest
+        - trove-tempest:
+            voting: false
     experimental:
       jobs:
         - trove-functional-mysql

trove/common/clients.py

@@ -19,7 +19,7 @@ from trove.common import cfg
 from trove.common import exception
 from trove.common.strategies.cluster import strategy
 
-from cinderclient.v2 import client as CinderClient
+from cinderclient.v3 import client as CinderClient
 import glanceclient
 from keystoneauth1.identity import v3
 from keystoneauth1 import session as ka_session

trove/tests/unittests/taskmanager/test_models.py

@@ -21,8 +21,8 @@ from unittest.mock import patch
 from unittest.mock import PropertyMock
 
 from cinderclient import exceptions as cinder_exceptions
-from cinderclient.v2 import volumes as cinderclient_volumes
-import cinderclient.v2.client as cinderclient
+from cinderclient.v3 import volumes as cinderclient_volumes
+import cinderclient.v3.client as cinderclient
 import neutronclient.v2_0.client as neutronclient
 from novaclient import exceptions as nova_exceptions
 import novaclient.v2.flavors