Remove six

Replace the following items with Python 3 style code.

- six.string_types
- six.integer_types
- six.moves
- six.PY2

Implements: blueprint six-removal

Change-Id: I2a0624bd4b455c7e5a0617f1253efa05485dc673

watcher/api/controllers/v1/service.py

@@ -19,8 +19,6 @@ Service mechanism provides ability to monitor Watcher services state.
 """
 
 import datetime
-import six
-
 from oslo_config import cfg
 from oslo_log import log
 from oslo_utils import timeutils
@@ -70,7 +68,7 @@ class Service(base.APIBase):
         service = objects.Service.get(pecan.request.context, id)
         last_heartbeat = (service.last_seen_up or service.updated_at or
                           service.created_at)
-        if isinstance(last_heartbeat, six.string_types):
+        if isinstance(last_heartbeat, str):
             # NOTE(russellb) If this service came in over rpc via
             # conductor, then the timestamp will be a string and needs to be
             # converted back to a datetime.

watcher/api/controllers/v1/types.py

@@ -15,7 +15,6 @@
 
 from oslo_serialization import jsonutils
 from oslo_utils import strutils
-import six
 import wsme
 from wsme import types as wtypes
 
@@ -132,7 +131,7 @@ class JsonType(wtypes.UserType):
 
     def __str__(self):
         # These are the json serializable native types
-        return ' | '.join(map(str, (wtypes.text, six.integer_types, float,
+        return ' | '.join(map(str, (wtypes.text, int, float,
                                     BooleanType, list, dict, None)))
 
     @staticmethod