Make sure test use the latest volume clients

Compute and scenario test use volume v2, but they should use
the latest available API version instead.

Change-Id: I09cfb726fe87b8e6a4f6ead7c955c77d60043d8b
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index feabe35..746f83a 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -97,8 +97,8 @@
         cls.security_group_default_rules_client = (
             cls.os_primary.security_group_default_rules_client)
         cls.versions_client = cls.os_primary.compute_versions_client
-
-        cls.volumes_client = cls.os_primary.volumes_v2_client
+        if CONF.service_available.cinder:
+            cls.volumes_client = cls.os_primary.volumes_client_latest
 
     @classmethod
     def resource_setup(cls):
diff --git a/tempest/clients.py b/tempest/clients.py
index d7a52d1..e617c3c 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -263,6 +263,7 @@
 
             # Set default client for users that don't need explicit version
             self.volumes_client_latest = self.volumes_v2_client
+            self.snapshots_client_latest = self.snapshots_v2_client
 
         if CONF.volume_feature_enabled.api_v3:
             self.backups_v3_client = self.volume_v3.BackupsClient()
@@ -277,6 +278,7 @@
 
             # Set default client for users that don't need explicit version
             self.volumes_client_latest = self.volumes_v3_client
+            self.snapshots_client_latest = self.snapshots_v3_client
 
     def _set_object_storage_clients(self):
         # NOTE(andreaf) Load configuration from config. Once object storage
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index 9b8c7a0..2843222 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -79,8 +79,10 @@
         cls.security_groups_client = cls.os_primary.security_groups_client
         cls.security_group_rules_client = (
             cls.os_primary.security_group_rules_client)
-        cls.volumes_client = cls.os_primary.volumes_v2_client
-        cls.snapshots_client = cls.os_primary.snapshots_v2_client
+        # Use the latest available volume clients
+        if CONF.service_available.cinder:
+            cls.volumes_client = cls.os_primary.volumes_client_latest
+            cls.snapshots_client = cls.os_primary.snapshots_client_latest
 
     # ## Test functions library
     #