Use config rather than hardcoded admin id from Quotas test
Use config rather than hardcoded admin id from Quotas test

Rather than use hardcoded 'admin' userid, get the
userid in the setUp() method in QuotasTestCase from the config
(CONF.identity.username).

Change-Id: I4c5ab05a9a55f9f9a093a0ff60f6793337863aa6
Closes-Bug: #1485762

cloudkeep/barbican,cloudkeep/barbican,openstack/barbican,openstack/barbican