Stage 1 conversion to JSON for storing Credentials.

Reviewed in http://codereview.appspot.com/4972065/
diff --git a/samples/prediction/prediction.py b/samples/prediction/prediction.py
index 3ffa974..1227019 100644
--- a/samples/prediction/prediction.py
+++ b/samples/prediction/prediction.py
@@ -109,7 +109,7 @@
 
     # Start training on a data set
     train = service.training()
-    body = {'id' : FLAGS.object_name}
+    body = {'id': FLAGS.object_name}
     start = train.insert(body=body).execute()
 
     print 'Started training'