Fix testing gate due to new keystoneclient release
Fix testing gate due to new keystoneclient release

As new keystoneclient version was released, token now
requires 'expires' field to be set.

Change-Id: I57a7746d24b82763824a02ac3d02049b055288c7
(cherry picked from commit 5a78832251e8cdf2dfbcc8b3a24ad8c4e7e3439c)

NeCTAR-RC/ceilometer,NeCTAR-RC/ceilometer,NeCTAR-RC/ceilometer