Full response for VolumesClient methods

Provide the entire response object for all methods of the
VolumeServicesClient

partially implements: blueprint method-return-value-and-move-service-clients-to-lib

Change-Id: I31c7ae14c514d736773db034baa5fe77e3f23370
diff --git a/tempest/stress/actions/volume_attach_delete.py b/tempest/stress/actions/volume_attach_delete.py
index 99e9eb6..7d1f975 100644
--- a/tempest/stress/actions/volume_attach_delete.py
+++ b/tempest/stress/actions/volume_attach_delete.py
@@ -30,7 +30,7 @@
         name = data_utils.rand_name("volume")
         self.logger.info("creating volume: %s" % name)
         volume = self.manager.volumes_client.create_volume(
-            display_name=name)
+            display_name=name)['volume']
         self.manager.volumes_client.wait_for_volume_status(volume['id'],
                                                            'available')
         self.logger.info("created volume: %s" % volume['id'])