Sync latest install_venv_common.py with olso
Sync latest install_venv_common.py with olso

This patch syncs with oslo change set of
> c78b2ab Avoid using cfg in install_venv_common

So that oslo-config isn't needed to run install_venv

Change-Id: Ia7ee923a53e09c0c6a525294ec4a5dc9d31c3bed
Fixes: bug #1131009
Signed-off-by: Isaku Yamahata <4b3abd66323411eeceff090ab3754dd766fc4b25@valinux.co.jp>

rickerc/neutron_audit,kaiweifan/vse-lbaas-plugin-poc,Comcast/neutron,Metaswitch/calico-neutron,netscaler/neutron,vijayendrabvs/ssl-neutron,CiscoSystems/quantum,liqin75/vse-vpnaas-plugin,magic0704/neutron,leeseuljeong/leeseulstack_neutron,yamt/neutron,jerryz1982/neutron,gopal1cloud/neutron,eonpatapon/neutron,yamahata/neutron,CiscoSystems/neutron,neoareslinux/neutron,bigswitch/neutron,shahbazn/neutron,mmnelemane/neutron,yamahata/tacker,bigswitch/neutron,cloudbase/neutron-virtualbox,NeCTAR-RC/neutron,jumpojoy/neutron,kaiweifan/vse-lbaas-plugin-poc,citrix-openstack-build/neutron,CiscoSystems/vespa,vijayendrabvs/hap,eayunstack/neutron,liqin75/vse-vpnaas-plugin,Juniper/neutron,aristanetworks/neutron,SamYaple/neutron,Stavitsky/neutron,virtualopensystems/neutron,virtualopensystems/neutron,Juniper/neutron,asgard-lab/neutron,ykaneko/neutron,rdo-management/neutron,zhhf/charging,swdream/neutron,ykaneko/quantum,yanheven/neutron,swdream/neutron,Juniper/neutron,beagles/neutron_hacking,liqin75/vse-vpnaas-plugin,rdo-management/neutron,cernops/neutron,miyakz1192/neutron,zhhf/charging,Brocade-OpenSource/OpenStack-DNRM-Neutron,kaiweifan/neutron,vijayendrabvs/ssl-neutron,blueboxgroup/neutron,bgxavier/neutron,virtualopensystems/neutron,gopal1cloud/neutron,wolverineav/neutron,adelina-t/neutron,gkotton/neutron,leeseulstack/openstack,sajuptpm/neutron-ipam,Juniper/contrail-dev-neutron,alexandrucoman/vbox-neutron-agent,adelina-t/neutron,eayunstack/neutron,javaos74/neutron,igor-toga/local-snat,neoareslinux/neutron,yamt/neutron,vbannai/neutron,vveerava/Openstack,jacknjzhou/neutron,projectcalico/calico-neutron,CiscoSystems/neutron,gkotton/neutron,redhat-openstack/neutron,ykaneko/quantum,jacknjzhou/neutron,watonyweng/neutron,watonyweng/neutron,yamt/neutron,jerryz1982/neutron,dims/neutron,mmnelemane/neutron,redhat-openstack/neutron,aristanetworks/neutron,Comcast/neutron,tpaszkowski/quantum,citrix-openstack-build/neutron,bgxavier/neutron,asgard-lab/neutron,infobloxopen/neutron,oeeagle/quantum,kaiweifan/neutron,vijayendrabvs/hap,beagles/neutron_hacking,blueboxgroup/neutron,beagles/neutron_hacking,cernops/neutron,vveerava/Openstack,kaiweifan/neutron,suneeth51/neutron,leeseulstack/openstack,takeshineshiro/neutron,vivekanand1101/neutron,yamahata/neutron,glove747/liberty-neutron,yamahata/neutron,miyakz1192/neutron,ntt-sic/neutron,sasukeh/neutron,openstack/neutron,Juniper/contrail-dev-neutron,yanheven/neutron,sasukeh/neutron,dhanunjaya/neutron,infobloxopen/neutron,CiscoSystems/vespa,openstack/neutron,pnavarro/neutron,leeseuljeong/leeseulstack_neutron,mandeepdhami/neutron,wenhuizhang/neutron,ykaneko/quantum,silenci/neutron,leeseuljeong/leeseulstack_neutron,mahak/neutron,CiscoSystems/quantum,SamYaple/neutron,Metaswitch/calico-neutron,yamahata/tacker,javaos74/neutron,mandeepdhami/neutron,MaximNevrov/neutron,tpaszkowski/quantum,paninetworks/neutron,CiscoSystems/neutron,apporc/neutron,cisco-openstack/neutron,Comcast/neutron,klmitch/neutron,barnsnake351/neutron,barnsnake351/neutron,magic0704/neutron,chitr/neutron,antonioUnina/neutron,mahak/neutron,rickerc/neutron_audit,vveerava/Openstack,jumpojoy/neutron,wenhuizhang/neutron,armando-migliaccio/neutron,openstack/neutron,skyddv/neutron,yamt/neutron,ntt-sic/neutron,apporc/neutron,cloudbase/neutron,huntxu/neutron,ntt-sic/neutron,projectcalico/calico-neutron,waltBB/neutron_read,vijayendrabvs/hap,Brocade-OpenSource/OpenStack-DNRM-Neutron,mattt416/neutron,liqin75/vse-vpnaas-plugin,blueboxgroup/neutron,mattt416/neutron,sebrandon1/neutron,Stavitsky/neutron,Brocade-OpenSource/OpenStack-DNRM-Neutron,paninetworks/neutron,igor-toga/local-snat,SmartInfrastructures/neutron,glove747/liberty-neutron,huntxu/neutron,dims/neutron,JioCloud/neutron,citrix-openstack-build/neutron,mahak/neutron,noironetworks/neutron,shahbazn/neutron,cisco-openstack/neutron,JioCloud/neutron,antonioUnina/neutron,dhanunjaya/neutron,NeCTAR-RC/neutron,klmitch/neutron,tpaszkowski/quantum,pnavarro/neutron,tpaszkowski/quantum,yamahata/tacker,alexandrucoman/vbox-neutron-agent,JianyuWang/neutron,takeshineshiro/neutron,kaiweifan/vse-lbaas-plugin-poc,CiscoSystems/quantum,cloudbase/neutron-virtualbox,silenci/neutron,MaximNevrov/neutron,cloudbase/neutron,ykaneko/quantum,yuewko/neutron,armando-migliaccio/neutron,vijayendrabvs/ssl-neutron,vbannai/neutron,JianyuWang/neutron,armando-migliaccio/neutron,eonpatapon/neutron,rickerc/neutron_audit,SmartInfrastructures/neutron,netscaler/neutron,chitr/neutron,kaiweifan/vse-lbaas-plugin-poc,sajuptpm/neutron-ipam,oeeagle/quantum,Juniper/contrail-dev-neutron,ykaneko/neutron,vbannai/neutron,CiscoSystems/vespa,zhhf/charging,netscaler/neutron,ykaneko/neutron,gkotton/neutron,waltBB/neutron_read,sebrandon1/neutron,vivekanand1101/neutron,armando-migliaccio/neutron,suneeth51/neutron,leeseulstack/openstack,sajuptpm/neutron-ipam,wolverineav/neutron,skyddv/neutron,yuewko/neutron,noironetworks/neutron