Add a docstring to hacking unit tests
Add a docstring to hacking unit tests

This commit adds a docstring to the hacking check unit tests
explaining how the tests work. To someone who isn't well versed with
how pep8/flake8 works the tests cases are a bit of black magic.

Change-Id: I5dc61612a5fec42443d8d89eaf700bb17b4b0842

rajalokan/nova,bigswitch/nova,scripnichenko/nova,JianyuWang/nova,whitepages/nova,Juniper/nova,Tehsmash/nova,CloudServer/nova,openstack/nova,double12gzh/nova,rahulunair/nova,viggates/nova,klmitch/nova,bgxavier/nova,tudorvio/nova,orbitfp7/nova,CEG-FYP-OpenStack/scheduler,yatinkumbhare/openstack-nova,eonpatapon/nova,tianweizhang/nova,fnordahl/nova,raildo/nova,CloudServer/nova,projectcalico/calico-nova,cernops/nova,devendermishrajio/nova,gooddata/openstack-nova,nikesh-mahalka/nova,phenoxim/nova,BeyondTheClouds/nova,felixma/nova,saleemjaveds/https-github.com-openstack-nova,Francis-Liu/animated-broccoli,rajalokan/nova,edulramirez/nova,Yusuke1987/openstack_template,yosshy/nova,Stavitsky/nova,Yusuke1987/openstack_template,mgagne/nova,mandeepdhami/nova,cyx1231st/nova,ruslanloman/nova,dims/nova,sebrandon1/nova,klmitch/nova,rahulunair/nova,hanlind/nova,cloudbase/nova,watonyweng/nova,devendermishrajio/nova_test_latest,cyx1231st/nova,gooddata/openstack-nova,cloudbase/nova,berrange/nova,viggates/nova,vladikr/nova_drafts,varunarya10/nova_test_latest,joker946/nova,rajalokan/nova,j-carpentier/nova,rahulunair/nova,projectcalico/calico-nova,iuliat/nova,belmiromoreira/nova,devendermishrajio/nova,cloudbase/nova-virtualbox,zhimin711/nova,bgxavier/nova,LoHChina/nova,MountainWei/nova,klmitch/nova,tangfeixiong/nova,alvarolopez/nova,shail2810/nova,Stavitsky/nova,double12gzh/nova,zzicewind/nova,JioCloud/nova,Juniper/nova,thomasem/nova,redhat-openstack/nova,eonpatapon/nova,tealover/nova,vmturbo/nova,sebrandon1/nova,dims/nova,mmnelemane/nova,redhat-openstack/nova,apporc/nova,virtualopensystems/nova,MountainWei/nova,yosshy/nova,hanlind/nova,noironetworks/nova,takeshineshiro/nova,barnsnake351/nova,scripnichenko/nova,JioCloud/nova_test_latest,mahak/nova,akash1808/nova,mandeepdhami/nova,JioCloud/nova_test_latest,phenoxim/nova,kimjaejoong/nova,Juniper/nova,affo/nova,blueboxgroup/nova,vmturbo/nova,adelina-t/nova,vladikr/nova_drafts,BeyondTheClouds/nova,CCI-MOC/nova,cloudbase/nova-virtualbox,devendermishrajio/nova_test_latest,fnordahl/nova,nikesh-mahalka/nova,joker946/nova,mahak/nova,zhimin711/nova,silenceli/nova,dawnpower/nova,maelnor/nova,JianyuWang/nova,gooddata/openstack-nova,varunarya10/nova_test_latest,barnsnake351/nova,petrutlucian94/nova,zzicewind/nova,ruslanloman/nova,virtualopensystems/nova,gooddata/openstack-nova,mahak/nova,badock/nova,CEG-FYP-OpenStack/scheduler,akash1808/nova_test_latest,jianghuaw/nova,jianghuaw/nova,belmiromoreira/nova,eayunstack/nova,orbitfp7/nova,thomasem/nova,mikalstill/nova,TwinkleChawla/nova,angdraug/nova,LoHChina/nova,blueboxgroup/nova,petrutlucian94/nova,ted-gould/nova,edulramirez/nova,alaski/nova,isyippee/nova,rajalokan/nova,vmturbo/nova,openstack/nova,cernops/nova,ted-gould/nova,TwinkleChawla/nova,shail2810/nova,alvarolopez/nova,jeffrey4l/nova,felixma/nova,Francis-Liu/animated-broccoli,iuliat/nova,tudorvio/nova,bigswitch/nova,sebrandon1/nova,Juniper/nova,tealover/nova,akash1808/nova_test_latest,saleemjaveds/https-github.com-openstack-nova,dawnpower/nova,cernops/nova,whitepages/nova,tanglei528/nova,mgagne/nova,Metaswitch/calico-nova,mikalstill/nova,NeCTAR-RC/nova,eayunstack/nova,vmturbo/nova,alexandrucoman/vbox-nova-driver,j-carpentier/nova,mmnelemane/nova,adelina-t/nova,berrange/nova,yatinkumbhare/openstack-nova,openstack/nova,klmitch/nova,tanglei528/nova,BeyondTheClouds/nova,tianweizhang/nova,zaina/nova,CCI-MOC/nova,watonyweng/nova,NeCTAR-RC/nova,hanlind/nova,alaski/nova,alexandrucoman/vbox-nova-driver,cloudbase/nova,apporc/nova,jianghuaw/nova,silenceli/nova,tangfeixiong/nova,Tehsmash/nova,jeffrey4l/nova,Metaswitch/calico-nova,badock/nova,affo/nova,angdraug/nova,JioCloud/nova,mikalstill/nova,isyippee/nova,kimjaejoong/nova,raildo/nova,noironetworks/nova,zaina/nova,takeshineshiro/nova,akash1808/nova,jianghuaw/nova,maelnor/nova