Fixed the blocking unittest issues.

1. Fixed the bug #1153921 introduced by the nova changeset
https://github.com/openstack/nova/commit/bd5a9b87.

2. Adapted to the latest keystoneclient middleware change introduced by
https://github.com/openstack/python-keystoneclient/commit/d782a998.

We must explicit set auth_version to prevent the middleware to
automatically detect its api version from remote keystone server in
unittest.

Change-Id: I439a74a7f9a8a62369ae50dc1d5e50e20f4d3574