Clean up database fixtures
Clean up database fixtures

 - Issues setting up the DB will now break early instead of causing
   issues later in tests.
 - Databases are now removed at the end of the test run.

Change-Id: I1dc5feafa9ae88fc0f2a4dd9459e7e34e2c4ce73

jamielennox/keystone,mahak/keystone,rushiagr/keystone,MaheshIBM/keystone,nuxeh/keystone,dstanek/keystone,ilay09/keystone,mahak/keystone,ging/keystone,promptworks/keystone,vivekdhayaal/keystone,maestro-hybrid-cloud/keystone,idjaw/keystone,cernops/keystone,jumpstarter-io/keystone,blueboxgroup/keystone,promptworks/keystone,ging/keystone,rodrigods/keystone,nuxeh/keystone,ilay09/keystone,takeshineshiro/keystone,JioCloud/keystone,himanshu-setia/keystone,vivekdhayaal/keystone,nuxeh/keystone,roopali8/keystone,ajayaa/keystone,JioCloud/keystone,rushiagr/keystone,reeshupatel/demo,openstack/keystone,jumpstarter-io/keystone,rajalokan/keystone,dstanek/keystone,reeshupatel/demo,takeshineshiro/keystone,rajalokan/keystone,MaheshIBM/keystone,dstanek/keystone,reeshupatel/demo,rajalokan/keystone,rodrigods/keystone,rushiagr/keystone,himanshu-setia/keystone,jonnary/keystone,ilay09/keystone,UTSA-ICS/keystone-kerberos,ajayaa/keystone,mahak/keystone,openstack/keystone,maestro-hybrid-cloud/keystone,roopali8/keystone,jonnary/keystone,klmitch/keystone,blueboxgroup/keystone,dims/keystone,jumpstarter-io/keystone,jamielennox/keystone,promptworks/keystone,dims/keystone,idjaw/keystone,UTSA-ICS/keystone-kerberos,openstack/keystone,vivekdhayaal/keystone,klmitch/keystone,cernops/keystone