Ignore warnings from contextlib.nested
Ignore warnings from contextlib.nested

We have a lot of warnings in py27 jobs about the
with statements that use contextlib.nested()
construct. We should just ignore them for now.

Alternatives tried included
- multiple manager form of the with statement which essentially
needed to be line wrapped with \ and would have caused a lot of
code changes.
- custom implementation of nested() turned out to be
more complicated than initially thought.

Change-Id: I1b8ed531be91faeb0067aad7338bd8868d16e50d

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