Add tempest tests for Consistency Groups

These tempest tests add coverage for all the API's related to
consistency groups in Cinder. They were originally proposed
for upstream tempest in https://review.openstack.org/#/c/252213/
but were not a good fit since they aren't supported by the
reference driver. They have been modified to work as part
of the in-tree tempest plugins for Cinder now.

The tests are behind a new config option for tempest, which
in turn is part of a new config group called 'cinder'. This
was added to avoid any collisions with the 'volume-features-enabled'
or 'volume' groups already in the upstream tempest tests.

To enable them set the following in tempest.conf

[cinder]
consistency_group = True

Then make sure to run tempest with the 'all-plugin' tox environment.

Don't forget to update policy.json to allow for CG API's to be called..

Change-Id: I772ea13ca156e71620d722eee476f222a8653831
Co-Authored-By: Xing Yang <xing.yang@emc.com>
diff --git a/cinder/tests/tempest/cinder_clients.py b/cinder/tests/tempest/cinder_clients.py
new file mode 100644
index 0000000..8f829ef
--- /dev/null
+++ b/cinder/tests/tempest/cinder_clients.py
@@ -0,0 +1,37 @@
+# Copyright (c) 2016 Pure Storage, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from tempest import config
+
+from cinder.tests.tempest.services import consistencygroups_client
+
+CONF = config.CONF
+
+
+class Manager(object):
+    def __init__(self, base_manager):
+        params = {
+            'service': CONF.volume.catalog_type,
+            'region': CONF.volume.region or CONF.identity.region,
+            'endpoint_type': CONF.volume.endpoint_type,
+            'build_interval': CONF.volume.build_interval,
+            'build_timeout': CONF.volume.build_timeout
+        }
+        params.update(base_manager.default_params)
+        auth_provider = base_manager.auth_provider
+
+        self.consistencygroups_adm_client = (
+            consistencygroups_client.ConsistencyGroupsClient(auth_provider,
+                                                             **params))