Add max-complexity to pep8 for Horizon
Add max-complexity to pep8 for Horizon

Picked this up from Keystone. It sounds like a good defense to have from
further making our code more complex.

The current highest complexity is 32, set the maximum complexity
for flake8 to 33. This should help to keep code simple and
maintainable. It should be possible to reduce the maximum
complexity to something closer to 20 with relatively small efforts.

openstack_dashboard.dashboards.identity.projects.workflows:
    'UpdateProject.handle' is complexity of 32
openstack_dashboard.dashboards.project.access_and_security.security_groups.forms:
    'AddRule.clean' is complexity of 20
openstack_dashboard.dashboards.project.instances.workflows.create_instance:
    'SetInstanceDetailsAction.clean' is complexity of 26
horizon.exceptions:
    'handle' is complexity of 24

Change-Id: I58cc20972aac221012f248e8135151b1243dae35

karthik-suresh/horizon,dan1/horizon-x509,damien-dg/horizon,django-leonardo/horizon,Metaswitch/horizon,openstack/horizon,NCI-Cloud/horizon,gerrive/horizon,j4/horizon,icloudrnd/automation_tools,watonyweng/horizon,Metaswitch/horizon,redhat-cip/horizon,xinwu/horizon,nvoron23/avos,idjaw/horizon,takeshineshiro/horizon,orbitfp7/horizon,izadorozhna/dashboard_integration_tests,maestro-hybrid-cloud/horizon,tsufiev/horizon,Dark-Hacker/horizon,Solinea/horizon,newrocknj/horizon,blueboxgroup/horizon,icloudrnd/automation_tools,wangxiangyu/horizon,NeCTAR-RC/horizon,coreycb/horizon,agileblaze/OpenStackTwoFactorAuthentication,watonyweng/horizon,saydulk/horizon,mdavid/horizon,kfox1111/horizon,FNST-OpenStack/horizon,NCI-Cloud/horizon,davidcusatis/horizon,yjxtogo/horizon,promptworks/horizon,pranavtendolkr/horizon,davidcusatis/horizon,Dark-Hacker/horizon,doug-fish/horizon,redhat-openstack/horizon,wangxiangyu/horizon,CiscoSystems/horizon,wangxiangyu/horizon,henaras/horizon,FNST-OpenStack/horizon,bigswitch/horizon,tqtran7/horizon,Daniex/horizon,endorphinl/horizon-fork,ging/horizon,Mirantis/mos-horizon,davidcusatis/horizon,Metaswitch/horizon,CiscoSystems/avos,dan1/horizon-proto,coreycb/horizon,tellesnobrega/horizon,kfox1111/horizon,watonyweng/horizon,liyitest/rr,eayunstack/horizon,endorphinl/horizon-fork,BiznetGIO/horizon,RudoCris/horizon,newrocknj/horizon,dan1/horizon-proto,Dark-Hacker/horizon,dan1/horizon-x509,django-leonardo/horizon,endorphinl/horizon,j4/horizon,Solinea/horizon,tsufiev/horizon,orbitfp7/horizon,ChameleonCloud/horizon,Daniex/horizon,mrunge/horizon_lib,j4/horizon,maestro-hybrid-cloud/horizon,ChameleonCloud/horizon,luhanhan/horizon,bac/horizon,newrocknj/horizon,NeCTAR-RC/horizon,VaneCloud/horizon,Tesora/tesora-horizon,CiscoSystems/avos,CiscoSystems/avos,NeCTAR-RC/horizon,Hodorable/0602,coreycb/horizon,Daniex/horizon,redhat-cip/horizon,saydulk/horizon,vladryk/horizon,endorphinl/horizon,agileblaze/OpenStackTwoFactorAuthentication,damien-dg/horizon,mandeepdhami/horizon,pranavtendolkr/horizon,redhat-openstack/horizon,RudoCris/horizon,noironetworks/horizon,yjxtogo/horizon,yeming233/horizon,liyitest/rr,agileblaze/OpenStackTwoFactorAuthentication,liyitest/rr,ChameleonCloud/horizon,nvoron23/avos,yeming233/horizon,henaras/horizon,eayunstack/horizon,liyitest/rr,endorphinl/horizon,Dark-Hacker/horizon,luhanhan/horizon,NCI-Cloud/horizon,tellesnobrega/horizon,wolverineav/horizon,Tesora/tesora-horizon,idjaw/horizon,mdavid/horizon,karthik-suresh/horizon,blueboxgroup/horizon,redhat-openstack/horizon,Mirantis/mos-horizon,luhanhan/horizon,noironetworks/horizon,philoniare/horizon,Mirantis/mos-horizon,django-leonardo/horizon,mrunge/openstack_horizon,Daniex/horizon,tsufiev/horizon,ging/horizon,eayunstack/horizon,icloudrnd/automation_tools,gerrive/horizon,mrunge/horizon_lib,bac/horizon,agileblaze/OpenStackTwoFactorAuthentication,tqtran7/horizon,NCI-Cloud/horizon,BiznetGIO/horizon,idjaw/horizon,Hodorable/0602,tqtran7/horizon,doug-fish/horizon,endorphinl/horizon-fork,xme1226/horizon,yjxtogo/horizon,VaneCloud/horizon,Hodorable/0602,mdavid/horizon,yeming233/horizon,philoniare/horizon,xinwu/horizon,BiznetGIO/horizon,vladryk/horizon,philoniare/horizon,dan1/horizon-proto,RudoCris/horizon,yeming233/horizon,ging/horizon,tellesnobrega/horizon,vladryk/horizon,saydulk/horizon,xme1226/horizon,yjxtogo/horizon,henaras/horizon,Tesora/tesora-horizon,idjaw/horizon,takeshineshiro/horizon,mandeepdhami/horizon,django-leonardo/horizon,CiscoSystems/avos,karthik-suresh/horizon,dan1/horizon-x509,Solinea/horizon,Mirantis/mos-horizon,wolverineav/horizon,gerrive/horizon,VaneCloud/horizon,takeshineshiro/horizon,Tesora/tesora-horizon,damien-dg/horizon,j4/horizon,redhat-cip/horizon,mdavid/horizon,maestro-hybrid-cloud/horizon,FNST-OpenStack/horizon,mrunge/openstack_horizon,davidcusatis/horizon,mandeepdhami/horizon,maestro-hybrid-cloud/horizon,pranavtendolkr/horizon,icloudrnd/automation_tools,wolverineav/horizon,kfox1111/horizon,takeshineshiro/horizon,RudoCris/horizon,philoniare/horizon,noironetworks/horizon,promptworks/horizon,doug-fish/horizon,blueboxgroup/horizon,NeCTAR-RC/horizon,promptworks/horizon,anthonydillon/horizon,anthonydillon/horizon,bigswitch/horizon,blueboxgroup/horizon,bigswitch/horizon,BiznetGIO/horizon,tsufiev/horizon,pranavtendolkr/horizon,endorphinl/horizon-fork,openstack/horizon,mrunge/horizon_lib,openstack/horizon,Hodorable/0602,xinwu/horizon,VaneCloud/horizon,vladryk/horizon,endorphinl/horizon,wangxiangyu/horizon,sandvine/horizon,nvoron23/avos,Metaswitch/horizon,xinwu/horizon,saydulk/horizon,redhat-openstack/horizon,henaras/horizon,mandeepdhami/horizon,izadorozhna/dashboard_integration_tests,watonyweng/horizon,promptworks/horizon,bigswitch/horizon,orbitfp7/horizon,damien-dg/horizon,sandvine/horizon,dan1/horizon-x509,luhanhan/horizon,redhat-cip/horizon,nvoron23/avos,bac/horizon,xme1226/horizon,bac/horizon,tellesnobrega/horizon,dan1/horizon-proto,noironetworks/horizon,anthonydillon/horizon,ging/horizon,doug-fish/horizon,CiscoSystems/horizon,CiscoSystems/horizon,openstack/horizon,CiscoSystems/horizon,wolverineav/horizon,Solinea/horizon,FNST-OpenStack/horizon,ChameleonCloud/horizon,gerrive/horizon,karthik-suresh/horizon,sandvine/horizon,mrunge/openstack_horizon,coreycb/horizon,orbitfp7/horizon,newrocknj/horizon,tqtran7/horizon,anthonydillon/horizon,sandvine/horizon,kfox1111/horizon