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: I7dd7a16d2b2d75120fa14de1d5c080a1a1c9729d

lower-constraints.txt

@@ -23,9 +23,7 @@ enmerkar==0.7.1
 extras==1.0.0
 fasteners==0.14.1
 fixtures==3.0.0
-flake8==2.5.5
 futurist==2.1.0
-hacking==0.12.0
 horizon==18.1.0
 idna==2.9
 imagesize==1.2.0
@@ -39,7 +37,6 @@ jsonschema==3.2.0
 keystoneauth1==3.18.0
 linecache2==1.0.0
 MarkupSafe==1.1.1
-mccabe==0.2.1
 mock==2.0
 monotonic==1.5
 mox3==1.0.0
@@ -65,10 +62,8 @@ oslosphinx==4.7.0
 osprofiler==2.3.0
 packaging==20.3
 pbr==2.0.0
-pep8==1.5.7
 prettytable==0.7.2
 pycparser==2.20
-pyflakes==0.8.1
 Pygments==2.6.1
 pyinotify==0.9.6
 pymongo==3.10.1

test-requirements.txt

@@ -7,7 +7,7 @@
 # be installed in a specific order.
 #
 # Hacking should appear first in case something else depends on pep8
-hacking>=0.12.0,!=0.13.0,<0.14 # Apache-2.0
+hacking>=3.0,<3.1 # Apache-2.0
 coverage>=4.0 # Apache-2.0
 nodeenv>=0.9.4 # BSD
 oslosphinx>=4.7.0 # Apache-2.0

tools/install_venv.py

@@ -67,5 +67,6 @@ def main(argv):
     install.install_dependencies()
     print_help(venv, root)
 
+
 if __name__ == '__main__':
     main(sys.argv)

tox.ini

@@ -58,7 +58,8 @@ deps =
 [flake8]
 exclude = .venv,.git,.tox,dist,*lib/python*,*egg,build,panel_template,dash_template,local_settings.py,*/local/*,*/test/test_plugins/*,.ropeproject,node_modules
 # These are currently not passing, should be removed once code is changed
-ignore = F405,H102,H301,H405,H701,H702
+# W504 line break after binary operator
+ignore = F405,H102,H301,H405,H701,H702,W504
 max-complexity = 20
 
 [hacking]