Add region name for identity and volume clients

We do not take into account region names for identity and volume
clients.

Change-Id: I4263e9013226b0adc6b9ad7540d6ad3efb42e809
Co-Authored-By: Eric Helgeson <erichelgeson@gmail.com>
Related-Bug: #1405416

openstackclient/identity/client.py

@@ -49,6 +49,7 @@ def make_client(instance):
     LOG.debug('Using auth plugin: %s' % instance._auth_plugin)
     client = identity_client(
         session=instance.session,
+        region_name=instance._region_name,
     )
 
     return client

openstackclient/volume/client.py

@@ -54,6 +54,7 @@ def make_client(instance):
         session=instance.session,
         extensions=extensions,
         http_log_debug=http_log_debug,
+        region_name=instance._region_name,
     )
 
     return client