Remove six library

Change-Id: Iadf31a4d5861cf1e821c6b4473ccec23899a2338
diff --git a/keystone_tempest_plugin/services/identity/clients.py b/keystone_tempest_plugin/services/identity/clients.py
index aac45d3..1baddc5 100644
--- a/keystone_tempest_plugin/services/identity/clients.py
+++ b/keystone_tempest_plugin/services/identity/clients.py
@@ -14,8 +14,7 @@
 
 import json
 
-import six
-from six.moves import http_client
+import http.client
 from tempest import config
 from tempest.lib.common import rest_client
 
@@ -53,26 +52,26 @@
     def _delete(self, entity_id, **kwargs):
         url = self._build_path(entity_id)
         resp, body = super(Federation, self).delete(url, **kwargs)
-        self.expected_success(http_client.NO_CONTENT, resp.status)
+        self.expected_success(http.client.NO_CONTENT, resp.status)
         return rest_client.ResponseBody(resp, body)
 
     def _get(self, entity_id=None, **kwargs):
         url = self._build_path(entity_id)
         resp, body = super(Federation, self).get(url, **kwargs)
-        self.expected_success(http_client.OK, resp.status)
-        body = json.loads(body if six.PY2 else body.decode('utf-8'))
+        self.expected_success(http.client.OK, resp.status)
+        body = json.loads(body.decode('utf-8'))
         return rest_client.ResponseBody(resp, body)
 
     def _patch(self, entity_id, body, **kwargs):
         url = self._build_path(entity_id)
         resp, body = super(Federation, self).patch(url, body, **kwargs)
-        self.expected_success(http_client.OK, resp.status)
-        body = json.loads(body if six.PY2 else body.decode('utf-8'))
+        self.expected_success(http.client.OK, resp.status)
+        body = json.loads(body.decode('utf-8'))
         return rest_client.ResponseBody(resp, body)
 
     def _put(self, entity_id, body, **kwargs):
         url = self._build_path(entity_id)
         resp, body = super(Federation, self).put(url, body, **kwargs)
-        self.expected_success(http_client.CREATED, resp.status)
-        body = json.loads(body if six.PY2 else body.decode('utf-8'))
+        self.expected_success(http.client.CREATED, resp.status)
+        body = json.loads(body.decode('utf-8'))
         return rest_client.ResponseBody(resp, body)