Sync install_venv_common from oslo
Sync install_venv_common from oslo

Change-Id: I9ecacefeb772af7efe0345c3b2162295c4999cdd

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