Enable exception format checking in the tests.
Enable exception format checking in the tests.

Updates the Keystone base test class so that we check for exception
formatting errors.

Change-Id: I168d8662752017050d63c83142f6fc45cd6fe38c

promptworks/keystone,maestro-hybrid-cloud/keystone,idjaw/keystone,citrix-openstack-build/keystone,ntt-sic/keystone,rajalokan/keystone,cbrucks/Federated_Keystone,takeshineshiro/keystone,townbull/keystone-dtrust,jumpstarter-io/keystone,UTSA-ICS/keystone-kerberos,vivekdhayaal/keystone,rajalokan/keystone,ilay09/keystone,rickerc/keystone_audit,nuxeh/keystone,cernops/keystone,vivekdhayaal/keystone,reeshupatel/demo,JioCloud/keystone,ajayaa/keystone,cloudbau/keystone,townbull/keystone-dtrust,dims/keystone,reeshupatel/demo,reeshupatel/demo,derekchiang/keystone,openstack/keystone,dsiddharth/access-keys,rushiagr/keystone,kwss/keystone,cernops/keystone,ntt-sic/keystone,blueboxgroup/keystone,nuxeh/keystone,promptworks/keystone,dstanek/keystone,maestro-hybrid-cloud/keystone,jonnary/keystone,jamielennox/keystone,ging/keystone,citrix-openstack-build/keystone,rajalokan/keystone,ntt-sic/keystone,rickerc/keystone_audit,cloudbau/keystone,rodrigods/keystone,rushiagr/keystone,idjaw/keystone,mahak/keystone,jumpstarter-io/keystone,ilay09/keystone,kwss/keystone,jumpstarter-io/keystone,MaheshIBM/keystone,rodrigods/keystone,cbrucks/Federated_Keystone,himanshu-setia/keystone,mahak/keystone,cloudbau/keystone,ging/keystone,rushiagr/keystone,klmitch/keystone,blueboxgroup/keystone,kwss/keystone,dims/keystone,dstanek/keystone,jonnary/keystone,himanshu-setia/keystone,openstack/keystone,nuxeh/keystone,townbull/keystone-dtrust,promptworks/keystone,cbrucks/Federated_Keystone,rickerc/keystone_audit,derekchiang/keystone,takeshineshiro/keystone,openstack/keystone,klmitch/keystone,vivekdhayaal/keystone,derekchiang/keystone,MaheshIBM/keystone,UTSA-ICS/keystone-kerberos,dsiddharth/access-keys,dsiddharth/access-keys,roopali8/keystone,mahak/keystone,ajayaa/keystone,JioCloud/keystone,ilay09/keystone,jamielennox/keystone,roopali8/keystone,citrix-openstack-build/keystone,dstanek/keystone