Fixes issue #85. Also moves all json imports to go through oauth2client.anyjson.  Reviewed in http://codereview.appspot.com/5531064/.
diff --git a/oauth2client/appengine.py b/oauth2client/appengine.py
index 723de8a..e4169e9 100644
--- a/oauth2client/appengine.py
+++ b/oauth2client/appengine.py
@@ -25,18 +25,9 @@
 import pickle
 import time
 
-try: # pragma: no cover
-  import simplejson
-except ImportError: # pragma: no cover
-  try:
-    # Try to import from django, should work on App Engine
-    from django.utils import simplejson
-  except ImportError:
-    # Should work for Python2.6 and higher.
-    import json as simplejson
-
 import clientsecrets
 
+from anyjson import simplejson
 from client import AccessTokenRefreshError
 from client import AssertionCredentials
 from client import Credentials