Cleanup the '_base' directory in libvirt tests.
Cleanup the '_base' directory in libvirt tests.

qwefi/nova,openstack/nova,KarimAllah/nova,SUSE-Cloud/nova,zhimin711/nova,eayunstack/nova,KarimAllah/nova,shootstar/novatest,jeffrey4l/nova,CCI-MOC/nova,salv-orlando/MyRepo,bgxavier/nova,cyx1231st/nova,tianweizhang/nova,NoBodyCam/TftpPxeBootBareMetal,rickerc/nova_audit,apporc/nova,dstroppa/openstack-smartos-nova-grizzly,eonpatapon/nova,berrange/nova,NoBodyCam/TftpPxeBootBareMetal,varunarya10/nova_test_latest,mmnelemane/nova,Yuriy-Leonov/nova,fajoy/nova,jianghuaw/nova,vladikr/nova_drafts,edulramirez/nova,rajalokan/nova,Metaswitch/calico-nova,klmitch/nova,akash1808/nova_test_latest,petrutlucian94/nova,fajoy/nova,psiwczak/openstack,BeyondTheClouds/nova,sileht/deb-openstack-nova,plumgrid/plumgrid-nova,Juniper/nova,raildo/nova,JioCloud/nova,dstroppa/openstack-smartos-nova-grizzly,savi-dev/nova,devendermishrajio/nova,josephsuh/extra-specs,rickerc/nova_audit,eneabio/nova,yrobla/nova,rahulunair/nova,vmturbo/nova,aristanetworks/arista-ovs-nova,thomasem/nova,vmturbo/nova,yosshy/nova,OpenAcademy-OpenStack/nova-scheduler,yrobla/nova,cloudbase/nova-virtualbox,felixma/nova,devoid/nova,Yuriy-Leonov/nova,NewpTone/stacklab-nova,cloudbase/nova,silenceli/nova,bclau/nova,salv-orlando/MyRepo,CEG-FYP-OpenStack/scheduler,josephsuh/extra-specs,joker946/nova,mgagne/nova,alvarolopez/nova,DirectXMan12/nova-hacking,bigswitch/nova,cloudbau/nova,usc-isi/nova,vmturbo/nova,watonyweng/nova,viggates/nova,viggates/nova,yatinkumbhare/openstack-nova,jeffrey4l/nova,NewpTone/stacklab-nova,CloudServer/nova,TwinkleChawla/nova,BeyondTheClouds/nova,SUSE-Cloud/nova,virtualopensystems/nova,adelina-t/nova,maoy/zknova,NewpTone/stacklab-nova,projectcalico/calico-nova,mahak/nova,psiwczak/openstack,whitepages/nova,sacharya/nova,sridevikoushik31/nova,NeCTAR-RC/nova,hanlind/nova,alaski/nova,houshengbo/nova_vmware_compute_driver,rajalokan/nova,maheshp/novatest,phenoxim/nova,petrutlucian94/nova,NoBodyCam/TftpPxeBootBareMetal,yosshy/nova,barnsnake351/nova,angdraug/nova,Tehsmash/nova,mandeepdhami/nova,NeCTAR-RC/nova,sridevikoushik31/nova,tudorvio/nova,virtualopensystems/nova,cernops/nova,zzicewind/nova,Triv90/Nova,russellb/nova,badock/nova,luogangyi/bcec-nova,silenceli/nova,iuliat/nova,zaina/nova,cyx1231st/nova,akash1808/nova_test_latest,russellb/nova,leilihh/nova,sridevikoushik31/openstack,gooddata/openstack-nova,TieWei/nova,bgxavier/nova,mahak/nova,DirectXMan12/nova-hacking,CCI-MOC/nova,blueboxgroup/nova,varunarya10/nova_test_latest,Francis-Liu/animated-broccoli,sileht/deb-openstack-nova,JianyuWang/nova,redhat-openstack/nova,gspilio/nova,jianghuaw/nova,thomasem/nova,plumgrid/plumgrid-nova,leilihh/nova,Yusuke1987/openstack_template,rahulunair/nova,ewindisch/nova,dims/nova,ntt-sic/nova,Metaswitch/calico-nova,zhimin711/nova,rajalokan/nova,mikalstill/nova,paulmathews/nova,akash1808/nova,eneabio/nova,Yusuke1987/openstack_template,klmitch/nova,fnordahl/nova,sebrandon1/nova,noironetworks/nova,OpenAcademy-OpenStack/nova-scheduler,Juniper/nova,Tehsmash/nova,sridevikoushik31/nova,hanlind/nova,maoy/zknova,Francis-Liu/animated-broccoli,double12gzh/nova,openstack/nova,sebrandon1/nova,citrix-openstack-build/nova,CiscoSystems/nova,cernops/nova,takeshineshiro/nova,alaski/nova,orbitfp7/nova,j-carpentier/nova,leilihh/novaha,phenoxim/nova,maelnor/nova,vmturbo/nova,cernops/nova,nikesh-mahalka/nova,ruslanloman/nova,alvarolopez/nova,affo/nova,psiwczak/openstack,bclau/nova,nikesh-mahalka/nova,usc-isi/extra-specs,double12gzh/nova,usc-isi/nova,iuliat/nova,gooddata/openstack-nova,mmnelemane/nova,shahar-stratoscale/nova,JioCloud/nova_test_latest,shahar-stratoscale/nova,tanglei528/nova,yatinkumbhare/openstack-nova,imsplitbit/nova,devoid/nova,usc-isi/extra-specs,ted-gould/nova,hanlind/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,TieWei/nova,tudorvio/nova,ntt-sic/nova,zaina/nova,felixma/nova,MountainWei/nova,alexandrucoman/vbox-nova-driver,leilihh/novaha,shail2810/nova,CiscoSystems/nova,badock/nova,saleemjaveds/https-github.com-openstack-nova,adelina-t/nova,CEG-FYP-OpenStack/scheduler,shail2810/nova,shootstar/novatest,eharney/nova,tangfeixiong/nova,spring-week-topos/nova-week,JioCloud/nova_test_latest,eonpatapon/nova,aristanetworks/arista-ovs-nova,edulramirez/nova,kimjaejoong/nova,tanglei528/nova,joker946/nova,Stavitsky/nova,Juniper/nova,dawnpower/nova,imsplitbit/nova,barnsnake351/nova,saleemjaveds/https-github.com-openstack-nova,BeyondTheClouds/nova,petrutlucian94/nova_dev,aristanetworks/arista-ovs-nova,sileht/deb-openstack-nova,tangfeixiong/nova,sridevikoushik31/openstack,alexandrucoman/vbox-nova-driver,mgagne/nova,paulmathews/nova,openstack/nova,noironetworks/nova,bigswitch/nova,ewindisch/nova,takeshineshiro/nova,savi-dev/nova,tealover/nova,luogangyi/bcec-nova,maelnor/nova,eharney/nova,devendermishrajio/nova_test_latest,scripnichenko/nova,eayunstack/nova,raildo/nova,orbitfp7/nova,usc-isi/nova,sridevikoushik31/nova,fnordahl/nova,Triv90/Nova,devendermishrajio/nova_test_latest,whitepages/nova,qwefi/nova,rrader/nova-docker-plugin,spring-week-topos/nova-week,vladikr/nova_drafts,josephsuh/extra-specs,maheshp/novatest,rahulunair/nova,gooddata/openstack-nova,cloudbase/nova-virtualbox,sebrandon1/nova,sridevikoushik31/openstack,KarimAllah/nova,projectcalico/calico-nova,JioCloud/nova,LoHChina/nova,dawnpower/nova,yrobla/nova,houshengbo/nova_vmware_compute_driver,redhat-openstack/nova,houshengbo/nova_vmware_compute_driver,savi-dev/nova,tealover/nova,isyippee/nova,cloudbau/nova,russellb/nova,dstroppa/openstack-smartos-nova-grizzly,JianyuWang/nova,blueboxgroup/nova,sacharya/nova,dims/nova,TwinkleChawla/nova,mikalstill/nova,isyippee/nova,devendermishrajio/nova,eneabio/nova,gspilio/nova,usc-isi/extra-specs,rajalokan/nova,tianweizhang/nova,apporc/nova,cloudbase/nova,paulmathews/nova,j-carpentier/nova,Triv90/Nova,jianghuaw/nova,akash1808/nova,scripnichenko/nova,citrix-openstack-build/nova,DirectXMan12/nova-hacking,watonyweng/nova,cloudbase/nova,zzicewind/nova,ruslanloman/nova,klmitch/nova,rrader/nova-docker-plugin,salv-orlando/MyRepo,gooddata/openstack-nova,berrange/nova,jianghuaw/nova,belmiromoreira/nova,ted-gould/nova,kimjaejoong/nova,CloudServer/nova,klmitch/nova,mahak/nova,mikalstill/nova,Brocade-OpenSource/OpenStack-DNRM-Nova,maoy/zknova,fajoy/nova,Stavitsky/nova,LoHChina/nova,gspilio/nova,petrutlucian94/nova_dev,Juniper/nova,maheshp/novatest,mandeepdhami/nova,affo/nova,MountainWei/nova,angdraug/nova,belmiromoreira/nova