Remove six[7]

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

Change-Id: I3738118b1898421ee41e9e2902c255ead73f3915

watcher/decision_engine/model/collector/base.py

@@ -110,7 +110,6 @@ import time
 
 from oslo_config import cfg
 from oslo_log import log
-import six
 
 from watcher.common import clients
 from watcher.common.loader import loadable
@@ -120,8 +119,8 @@ LOG = log.getLogger(__name__)
 CONF = cfg.CONF
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseClusterDataModelCollector(loadable.LoadableSingleton):
+class BaseClusterDataModelCollector(loadable.LoadableSingleton,
+                                    metaclass=abc.ABCMeta):
 
     STALE_MODEL = model_root.ModelRoot(stale=True)
 

watcher/decision_engine/model/collector/cinder.py

@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import six
-
 from oslo_log import log
 
 from watcher.common import cinder_helper
@@ -286,7 +284,7 @@ class CinderModelBuilder(base.BaseModelBuilder):
         :param instance: Cinder Volume object.
         :return: A volume node for the graph.
         """
-        attachments = [{k: v for k, v in six.iteritems(d) if k in (
+        attachments = [{k: v for k, v in iter(d.items()) if k in (
             'server_id', 'attachment_id')} for d in volume.attachments]
 
         volume_attributes = {