Made the tenant xsd extensible.
Made the tenant xsd extensible.

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