Accept 201 status code on POST

On POST requests, keystone should return '201 Created' according to
api docs.

Related to but not dependent on:
https://bugs.launchpad.net/keystone/+bug/1131119

Change-Id: I04c398ad7946f5ddcfd2059e4f8d97608e5d0ed3

novaclient/client.py

@@ -240,7 +240,8 @@ class HTTPClient(object):
         We may get redirected to another site, fail or actually get
         back a service catalog with a token and our endpoints."""
 
-        if resp.status_code == 200:  # content must always present
+        # content must always present
+        if resp.status_code == 200 or resp.status_code == 201:
             try:
                 self.auth_url = url
                 self.service_catalog = \