Update flake8 pinned versions.
Update flake8 pinned versions.

We've learned this lesson the hard way in the past...

Change-Id: I02c75853234c16f3666185998202431cc7a4f2eb

glove747/liberty-neutron,vijayendrabvs/hap,armando-migliaccio/neutron,ntt-sic/neutron,huntxu/neutron,ykaneko/quantum,infobloxopen/neutron,vijayendrabvs/ssl-neutron,apporc/neutron,ykaneko/neutron,sebrandon1/neutron,suneeth51/neutron,dims/neutron,leeseulstack/openstack,netscaler/neutron,CiscoSystems/quantum,asgard-lab/neutron,virtualopensystems/neutron,Comcast/neutron,waltBB/neutron_read,JianyuWang/neutron,CiscoSystems/vespa,jumpojoy/neutron,alexandrucoman/vbox-neutron-agent,sajuptpm/neutron-ipam,Juniper/contrail-dev-neutron,asgard-lab/neutron,leeseuljeong/leeseulstack_neutron,noironetworks/neutron,virtualopensystems/neutron,mahak/neutron,glove747/liberty-neutron,magic0704/neutron,dims/neutron,mmnelemane/neutron,kaiweifan/neutron,Brocade-OpenSource/OpenStack-DNRM-Neutron,alexandrucoman/vbox-neutron-agent,ntt-sic/neutron,beagles/neutron_hacking,mahak/neutron,vivekanand1101/neutron,openstack/neutron,CiscoSystems/vespa,zhhf/charging,miyakz1192/neutron,citrix-openstack-build/neutron,yamahata/tacker,yuewko/neutron,wenhuizhang/neutron,MaximNevrov/neutron,chitr/neutron,oeeagle/quantum,Metaswitch/calico-neutron,gopal1cloud/neutron,eonpatapon/neutron,dhanunjaya/neutron,vijayendrabvs/ssl-neutron,ykaneko/neutron,shahbazn/neutron,cloudbase/neutron,Stavitsky/neutron,ykaneko/quantum,bigswitch/neutron,sasukeh/neutron,silenci/neutron,mahak/neutron,yuewko/neutron,magic0704/neutron,CiscoSystems/neutron,virtualopensystems/neutron,CiscoSystems/neutron,citrix-openstack-build/neutron,neoareslinux/neutron,miyakz1192/neutron,pnavarro/neutron,ykaneko/quantum,redhat-openstack/neutron,skyddv/neutron,kaiweifan/neutron,javaos74/neutron,yanheven/neutron,waltBB/neutron_read,takeshineshiro/neutron,NeCTAR-RC/neutron,gkotton/neutron,leeseuljeong/leeseulstack_neutron,klmitch/neutron,bgxavier/neutron,eayunstack/neutron,blueboxgroup/neutron,adelina-t/neutron,adelina-t/neutron,jerryz1982/neutron,jumpojoy/neutron,blueboxgroup/neutron,vijayendrabvs/hap,sajuptpm/neutron-ipam,beagles/neutron_hacking,gkotton/neutron,barnsnake351/neutron,gopal1cloud/neutron,oeeagle/quantum,CiscoSystems/neutron,pnavarro/neutron,zhhf/charging,cernops/neutron,aristanetworks/neutron,yamahata/neutron,mattt416/neutron,JioCloud/neutron,bigswitch/neutron,beagles/neutron_hacking,jacknjzhou/neutron,chitr/neutron,yamahata/tacker,paninetworks/neutron,antonioUnina/neutron,javaos74/neutron,yamahata/neutron,mandeepdhami/neutron,cisco-openstack/neutron,yamahata/neutron,rdo-management/neutron,projectcalico/calico-neutron,SmartInfrastructures/neutron,vbannai/neutron,kaiweifan/neutron,Juniper/neutron,MaximNevrov/neutron,vijayendrabvs/hap,JianyuWang/neutron,Juniper/contrail-dev-neutron,yanheven/neutron,Brocade-OpenSource/OpenStack-DNRM-Neutron,noironetworks/neutron,huntxu/neutron,vbannai/neutron,blueboxgroup/neutron,cisco-openstack/neutron,neoareslinux/neutron,bgxavier/neutron,CiscoSystems/quantum,igor-toga/local-snat,igor-toga/local-snat,openstack/neutron,cloudbase/neutron,paninetworks/neutron,vveerava/Openstack,dhanunjaya/neutron,barnsnake351/neutron,aristanetworks/neutron,SamYaple/neutron,CiscoSystems/quantum,ykaneko/neutron,vveerava/Openstack,gkotton/neutron,cloudbase/neutron-virtualbox,leeseuljeong/leeseulstack_neutron,watonyweng/neutron,JioCloud/neutron,rdo-management/neutron,swdream/neutron,wenhuizhang/neutron,redhat-openstack/neutron,cernops/neutron,armando-migliaccio/neutron,leeseulstack/openstack,projectcalico/calico-neutron,eonpatapon/neutron,mandeepdhami/neutron,openstack/neutron,klmitch/neutron,vijayendrabvs/ssl-neutron,Juniper/contrail-dev-neutron,ykaneko/quantum,wolverineav/neutron,vivekanand1101/neutron,apporc/neutron,vveerava/Openstack,Comcast/neutron,Juniper/neutron,Brocade-OpenSource/OpenStack-DNRM-Neutron,silenci/neutron,shahbazn/neutron,vbannai/neutron,rickerc/neutron_audit,sasukeh/neutron,Stavitsky/neutron,sebrandon1/neutron,armando-migliaccio/neutron,rickerc/neutron_audit,takeshineshiro/neutron,armando-migliaccio/neutron,eayunstack/neutron,rickerc/neutron_audit,mmnelemane/neutron,watonyweng/neutron,Metaswitch/calico-neutron,yamahata/tacker,SamYaple/neutron,Comcast/neutron,jacknjzhou/neutron,cloudbase/neutron-virtualbox,netscaler/neutron,sajuptpm/neutron-ipam,mattt416/neutron,swdream/neutron,NeCTAR-RC/neutron,wolverineav/neutron,netscaler/neutron,ntt-sic/neutron,skyddv/neutron,infobloxopen/neutron,leeseulstack/openstack,antonioUnina/neutron,Juniper/neutron,CiscoSystems/vespa,jerryz1982/neutron,SmartInfrastructures/neutron,zhhf/charging,citrix-openstack-build/neutron,suneeth51/neutron