Updated openstack/openstack
Project: openstack/keystonemiddleware  139e1fcf03746348370100e0764e5d06ba4f8be3

Change occurrences of keystone to identity server

The auth token middleware referred to Keystone everywhere, but
Keystone is only one possible implementation of the identity API.
The code should refer to the identity API or identity server where
appropriate.

Change-Id: I67a0c203a4e0482b36b021e98e8ac99e29b0c2df