Update hacking for Python3

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

Blacklist:
W503 line break before binary operator
W504 line break after binary operator

Fix:
E123 closing bracket does not match indentation of opening bracket's line
E126 continuation line over-indented for hanging indent

Change-Id: I39003496a3f4be5a4cb05cdbae53a9c097e34e14

oslo_policy/tests/test_generator.py

@@ -595,7 +595,7 @@ class ListRedundantTestCase(base.PolicyBaseTestCase):
                                deprecated_rule=deprecated_rule,
                                deprecated_reason='reason',
                                deprecated_since='T')
-            )
+        )
 
         # Mock out stevedore to return the configured enforcer
         ext = stevedore.extension.Extension(name='testing', entry_point=None,

oslo_policy/tests/test_sphinxpolicygen.py

@@ -73,8 +73,8 @@ class SingleSampleGenerationTest(base.BaseTestCase):
             mock.call(args=[
                 '--config-file', '/opt/nova/nova.conf',
                 '--output-file', '/opt/nova/nova.policy.yaml.sample'],
-                      conf=mock.ANY),
+                conf=mock.ANY),
             mock.call(args=[
                 '--config-file', '/opt/nova/placement.conf',
                 '--output-file', '/opt/nova/placement.policy.yaml.sample'],
-                      conf=mock.ANY)])
+                conf=mock.ANY)])

test-requirements.txt

@@ -1,7 +1,7 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-hacking>=1.1.0,<1.2.0 # Apache-2.0
+hacking>=3.0,<3.1.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 requests-mock>=1.2.0 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0

tox.ini

@@ -44,7 +44,9 @@ commands =
 
 [flake8]
 show-source = True
-ignore =
+# W503 line break before binary operator
+# W504 line break after binary operator
+ignore = W503,W504
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build