Update hacking for Python3

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

Fix problems found.

Remove hacking and friends from lower-constraints, they are not needed
for installation.

Change-Id: I0564dc6c961a55387a430f095ed83b392a81c119

lower-constraints.txt

@@ -12,11 +12,9 @@ eventlet==0.22.0
 extras==1.0.0
 fasteners==0.7.0
 fixtures==3.0.0
-flake8==2.5.5
 gitdb==0.6.4
 GitPython==1.0.1
 greenlet==0.4.10
-hacking==0.12.0
 imagesize==0.7.1
 iso8601==0.1.11
 Jinja2==2.10
@@ -43,8 +41,6 @@ oslotest==3.2.0
 Paste==2.0.2
 PasteDeploy==1.5.0
 pbr==2.0.0
-pep8==1.5.7
-pyflakes==0.8.1
 Pygments==2.2.0
 pyinotify==0.9.6
 pyparsing==2.1.0

test-requirements.txt

@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 
 fixtures>=3.0.0 # Apache-2.0/BSD
-hacking>=1.1.0,<1.2.0 # Apache-2.0
+hacking>=3.0,<3.1.0 # Apache-2.0
 mock>=2.0.0 # BSD
 oslotest>=3.2.0 # Apache-2.0
 requests>=2.14.2 # Apache-2.0

tox.ini

@@ -41,9 +41,9 @@ commands = python setup.py test --coverage --coverage-package-name=oslo_service
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
 # E731 skipped as assign a lambda expression
-
+# W504 line break after binary operator
 show-source = True
-ignore = E123,E125,E731
+ignore = E123,E125,E731,W504
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 
 [hacking]