Updated openstack/openstack
Project: openstack/keystonemiddleware  f0ada66342847e8d592f86570ca1c2b11e491e96

Fix reference to middleware architecture doc

The auth_token docstring was referencing the middleware architecture
doc in keystoneclient. Updated to the new location.

Change-Id: I495bc332230f75e579e03c1b6f8feba49a26e5bf