Switch cinder to cinderv2

Cinderv1 has been deprecated and removed, we even do not enable it
in MCP installations. This patch switch tempest to use cinderv2 endpoint
by default.

Change-Id: Ie40714b34592b19d95fba646cf6b4c8862db49ae
diff --git a/_modules/runtest/tempest_sections/volume.py b/_modules/runtest/tempest_sections/volume.py
index c30e274..a575389 100644
--- a/_modules/runtest/tempest_sections/volume.py
+++ b/_modules/runtest/tempest_sections/volume.py
@@ -38,7 +38,7 @@
 
     @property
     def catalog_type(self):
-        pass
+        return 'volumev2'
 
     @property
     def disk_format(self):