Fix PEP8 failures for H236, remove unneeded ignores, use newer hacking

Fix [H236] Use six.add_metaclass instead of __metaclass__.

Remove ignoring of: H233, H234, and H236 as they are passing.

Use hacking>=1.0.0

Change-Id: I310f1161467339c6784bae253e0e3713f23d5218

storyboard/plugin/email/workers.py

@@ -49,8 +49,6 @@ class EmailWorkerBase(EmailPluginBase, WorkerTaskBase):
     building emails off of our event queue.
     """
 
-    __metaclass__ = abc.ABCMeta
-
     def handle(self, session, author, method, url, path, query_string, status,
                resource, resource_id, sub_resource=None, sub_resource_id=None,
                resource_before=None, resource_after=None):

storyboard/plugin/event_worker.py

@@ -19,6 +19,7 @@ from threading import Timer
 
 from oslo_config import cfg
 from oslo_log import log
+import six
 
 import storyboard.db.api.base as db_api
 from storyboard.notifications.notification_hook import class_mappings
@@ -157,11 +158,10 @@ class PerpetualTimer(object):
             self.thread.cancel()
 
 
+@six.add_metaclass(abc.ABCMeta)
 class WorkerTaskBase(PluginBase):
     """Base class for a worker that listens to API Events."""
 
-    __metaclass__ = abc.ABCMeta
-
     def event(self, author_id, method, url, path, query_string, status,
               resource, resource_id, sub_resource=None, sub_resource_id=None,
               resource_before=None, resource_after=None):

test-requirements.txt

@@ -1,4 +1,4 @@
-hacking>=0.11.0,<0.12
+hacking>=1.0.0
 
 coverage>=3.6
 fixtures>=0.3.14

tox.ini

@@ -46,12 +46,9 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
 # E125 and E128 are ignored on purpose, they are invalid pep8
 # The following rules should either be addressed or determined to be
 # skippable long term.
-# H405 is ignored to make switch to newer hacking easier
-# H234 is ignored to make switch to newer hacking easier
-# H233 is ignored to make switch to newer hacking easier
 # E265 is ignored to make switch to newer hacking easier
-# H236 is ignored to make switch to newer hacking easier
-ignore = E125,E128,H405,H234,H233,E265,H236
+# H405 is ignored to make switch to newer hacking easier
+ignore = E125,E128,E265,H405
 builtins = _
 show-source = True
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build