initialize environment for tests that call popen
initialize environment for tests that call popen

Change-Id: I5b367f7f97de353f12e41dc7768a7fcdc740eabd

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