Update hacking for Python3

The repo is Python 3 now, so update hacking to version 3.0 which
supports Python 3.

blacklist:
W504 line break after binary operator
E731 do not assign a lambda expression, use a def

Change-Id: I5099674e8813a070f34ba4fa4a26f2b61acad925

test-requirements.txt

@@ -2,7 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking<0.11,>=0.10.0
+hacking>=3.0,<3.1.0 # Apache-2.0
 
 # Used for making sure the eventlet executors work.
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT

tox.ini

@@ -48,7 +48,7 @@ commands = oslo_debug_helper {posargs}
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
 show-source = True
-ignore = E123,E125
+ignore = E123,E125,E731,W504
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 
 [testenv:releasenotes]