initialize objects with context in network manager tests
initialize objects with context in network manager tests

These changes aim to clean up the pattern of passing a context in
object member functions create/destroy/refresh/save and instead
initialize the object with the context when it's constructed.

Related to blueprint kilo-objects

Change-Id: Ia27e0952d396f1a4c9c520faeeb18517a394ab9b

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