Clean up pep8 E711 violations

Fixed E711 errors
All ignores are to be removed in the next sequence of patches

Change-Id: Id9bcdfa276d30639dc6d16b8ce6db19101153fcd
diff --git a/tempest/services/identity/json/admin_client.py b/tempest/services/identity/json/admin_client.py
index a42a690..aa3a52a 100644
--- a/tempest/services/identity/json/admin_client.py
+++ b/tempest/services/identity/json/admin_client.py
@@ -226,7 +226,7 @@
     def request(self, method, url, headers=None, body=None):
         """A simple HTTP request interface."""
         self.http_obj = httplib2.Http()
-        if headers == None:
+        if headers is None:
             headers = {}
 
         resp, resp_body = self.http_obj.request(url, method,