libvirt: avoid 30 second long test in LXC mount setup
libvirt: avoid 30 second long test in LXC mount setup

The test_create_propagates_exceptions test case in the libvirt
driver test has a 30 second delay while disk setup times out.

  File "nova/virt/libvirt/driver.py", line 4412, in _create_domain_and_network
    disk_info):
  File "/usr/lib64/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "nova/virt/libvirt/driver.py", line 4308, in _lxc_disk_handler
    self._create_domain_setup_lxc(instance, block_device_info, disk_info)
  File "nova/virt/libvirt/driver.py", line 4260, in _create_domain_setup_lxc
    use_cow=use_cow)
  File "nova/virt/disk/api.py", line 386, in setup_container
    dev = img.mount()
  File "nova/virt/disk/api.py", line 306, in mount
    if mounter.do_mount():
  File "nova/virt/disk/mount/api.py", line 218, in do_mount
    status = self.get_dev() and self.map_dev() and self.mnt_dev()
  File "nova/virt/disk/mount/nbd.py", line 120, in get_dev
    return self._get_dev_retry_helper()
  File "nova/virt/disk/mount/api.py", line 121, in _get_dev_retry_helper
    time.sleep(2)

Mock out the _create_domain_setup_lxc & _create_domain_cleanup_lxc
methods to avoid exercising this codepath which is irrelevant to the
goals of the test case.

Resolves-bug: #1369537
Change-Id: Ic860f83ac0b3b7242658640618b223d89c4db253

adelina-t/nova,devendermishrajio/nova,hanlind/nova,vmturbo/nova,ruslanloman/nova,watonyweng/nova,Stavitsky/nova,CEG-FYP-OpenStack/scheduler,JioCloud/nova_test_latest,kimjaejoong/nova,barnsnake351/nova,bgxavier/nova,barnsnake351/nova,MountainWei/nova,rajalokan/nova,klmitch/nova,mahak/nova,CloudServer/nova,openstack/nova,angdraug/nova,CloudServer/nova,affo/nova,phenoxim/nova,rajalokan/nova,gooddata/openstack-nova,JioCloud/nova,mmnelemane/nova,vmturbo/nova,sebrandon1/nova,devendermishrajio/nova_test_latest,eonpatapon/nova,Metaswitch/calico-nova,klmitch/nova,gooddata/openstack-nova,cyx1231st/nova,CEG-FYP-OpenStack/scheduler,dims/nova,yosshy/nova,zzicewind/nova,apporc/nova,double12gzh/nova,berrange/nova,dawnpower/nova,blueboxgroup/nova,takeshineshiro/nova,zzicewind/nova,silenceli/nova,MountainWei/nova,scripnichenko/nova,noironetworks/nova,ted-gould/nova,cernops/nova,cloudbase/nova-virtualbox,Juniper/nova,yosshy/nova,isyippee/nova,NeCTAR-RC/nova,whitepages/nova,tangfeixiong/nova,akash1808/nova,badock/nova,shail2810/nova,eayunstack/nova,projectcalico/calico-nova,alvarolopez/nova,Juniper/nova,devendermishrajio/nova,sebrandon1/nova,alaski/nova,whitepages/nova,devendermishrajio/nova_test_latest,zaina/nova,rahulunair/nova,klmitch/nova,mgagne/nova,hanlind/nova,tudorvio/nova,jianghuaw/nova,eayunstack/nova,varunarya10/nova_test_latest,rajalokan/nova,adelina-t/nova,LoHChina/nova,TwinkleChawla/nova,CCI-MOC/nova,mandeepdhami/nova,JioCloud/nova_test_latest,takeshineshiro/nova,iuliat/nova,maelnor/nova,thomasem/nova,affo/nova,tudorvio/nova,blueboxgroup/nova,BeyondTheClouds/nova,gooddata/openstack-nova,BeyondTheClouds/nova,ted-gould/nova,rahulunair/nova,orbitfp7/nova,vladikr/nova_drafts,mikalstill/nova,bgxavier/nova,JianyuWang/nova,orbitfp7/nova,badock/nova,rahulunair/nova,Juniper/nova,j-carpentier/nova,thomasem/nova,angdraug/nova,joker946/nova,jianghuaw/nova,belmiromoreira/nova,ruslanloman/nova,scripnichenko/nova,redhat-openstack/nova,petrutlucian94/nova,felixma/nova,jianghuaw/nova,vmturbo/nova,nikesh-mahalka/nova,cernops/nova,Metaswitch/calico-nova,alexandrucoman/vbox-nova-driver,phenoxim/nova,dawnpower/nova,varunarya10/nova_test_latest,Yusuke1987/openstack_template,yatinkumbhare/openstack-nova,hanlind/nova,mandeepdhami/nova,mmnelemane/nova,openstack/nova,isyippee/nova,cernops/nova,nikesh-mahalka/nova,Francis-Liu/animated-broccoli,fnordahl/nova,berrange/nova,alvarolopez/nova,apporc/nova,vmturbo/nova,Tehsmash/nova,j-carpentier/nova,yatinkumbhare/openstack-nova,Tehsmash/nova,CCI-MOC/nova,Juniper/nova,kimjaejoong/nova,petrutlucian94/nova,belmiromoreira/nova,Francis-Liu/animated-broccoli,cloudbase/nova,noironetworks/nova,openstack/nova,tealover/nova,edulramirez/nova,NeCTAR-RC/nova,bigswitch/nova,alaski/nova,raildo/nova,felixma/nova,cloudbase/nova,silenceli/nova,cyx1231st/nova,cloudbase/nova-virtualbox,LoHChina/nova,akash1808/nova,projectcalico/calico-nova,zaina/nova,eonpatapon/nova,watonyweng/nova,tianweizhang/nova,bigswitch/nova,redhat-openstack/nova,raildo/nova,sebrandon1/nova,jeffrey4l/nova,JioCloud/nova,klmitch/nova,tianweizhang/nova,shail2810/nova,Stavitsky/nova,fnordahl/nova,mikalstill/nova,tangfeixiong/nova,rajalokan/nova,vladikr/nova_drafts,mikalstill/nova,iuliat/nova,akash1808/nova_test_latest,jeffrey4l/nova,maelnor/nova,jianghuaw/nova,cloudbase/nova,akash1808/nova_test_latest,zhimin711/nova,tealover/nova,mgagne/nova,BeyondTheClouds/nova,TwinkleChawla/nova,alexandrucoman/vbox-nova-driver,mahak/nova,mahak/nova,edulramirez/nova,Yusuke1987/openstack_template,JianyuWang/nova,double12gzh/nova,gooddata/openstack-nova,zhimin711/nova,joker946/nova,dims/nova