Cleanup tools/hacking using flake8
Cleanup tools/hacking using flake8

Change-Id: Ia151f265bf62e6704de6cc2f2c01963be9e2dd69

emonty/oslo-hacking,hyakuhei/cleantox,hyakuhei/cleantox,emonty/oslo-hacking,openstack-dev/hacking,openstack-dev/hacking,zancas/hacking,zancas/hacking