fix typo in identity/v3/endpoint.py

Change-Id: Idf57a6a988f5c0f20f3b0b19ab896642ce10d70b
use ksc.session

Use the Session object from keystoneclient in our libraries

* Create auth plugin and session objects explicitly
* Remove restapi.py
* Change object-store commands to use keystoneclient.session.Session
* Update tests

Change-Id: I47ec63291e4c3cf36c8061299a4764f60b36ab89
Merge branch 'ksc-session' into dt-test
Merge branch 'compute-test-fix' into dt-test
Merge branch 'identity-ec2-tests' into dt-test