Use anyjson consistently.

Reviewed in http://codereview.appspot.com/6343090/.
diff --git a/describe.py b/describe.py
index 0951285..87dcd0c 100644
--- a/describe.py
+++ b/describe.py
@@ -23,7 +23,6 @@
 
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'
 
-import json
 import os
 import re
 import sys
@@ -328,7 +327,7 @@
               'api': name,
               'apiVersion': version})
           )
-  discovery = json.loads(content)
+  discovery = simplejson.loads(content)
 
   version = safe_version(version)