Fix auth info on scrubber tests
Fix auth info on scrubber tests

The scrubber tests do not pass suitable HTTP headers to pass any
of the policy checks we are going to start adding. This just imports
the base header template from other functional tests so that the
context that is constructed has a proper tenant member arrangement.

Change-Id: I350499b4b3f326ade2c64a2d50e1562c413e449a

openstack/glance,openstack/glance,openstack/glance