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)