Remove six[7]

Since our code will only support py3. So remove six is necessary.

Change-Id: I3738118b1898421ee41e9e2902c255ead73f3915

watcher/applier/action_plan/base.py

@@ -18,11 +18,9 @@
 #
 
 import abc
-import six
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseActionPlanHandler(object):
+class BaseActionPlanHandler(object, metaclass=abc.ABCMeta):
     @abc.abstractmethod
     def execute(self):
         raise NotImplementedError()

watcher/applier/actions/base.py

@@ -19,14 +19,12 @@
 import abc
 
 import jsonschema
-import six
 
 from watcher.common import clients
 from watcher.common.loader import loadable
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseAction(loadable.Loadable):
+class BaseAction(loadable.Loadable, metaclass=abc.ABCMeta):
     # NOTE(jed): by convention we decided
     # that the attribute "resource_id" is the unique id of
     # the resource to which the Action applies to allow us to use it in the

watcher/applier/base.py

@@ -26,11 +26,9 @@ See: :doc:`../architecture` for more details on this component.
 """
 
 import abc
-import six
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseApplier(object):
+class BaseApplier(object, metaclass=abc.ABCMeta):
     @abc.abstractmethod
     def execute(self, action_plan_uuid):
         raise NotImplementedError()

watcher/applier/workflow_engine/base.py

@@ -17,7 +17,6 @@
 #
 
 import abc
-import six
 import time
 
 import eventlet
@@ -40,8 +39,7 @@ CANCEL_STATE = [objects.action_plan.State.CANCELLING,
                 objects.action_plan.State.CANCELLED]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseWorkFlowEngine(loadable.Loadable):
+class BaseWorkFlowEngine(loadable.Loadable, metaclass=abc.ABCMeta):
 
     def __init__(self, config, context=None, applier_manager=None):
         """Constructor