New package structure for the version 2 of the public api.

Start building up the validators required for post notificaiton.
The app/v2/errors.py is a rough sketch, will be passed a code, the error can look up the message and link for the error message.

app/schema_validation/__init__.py

@@ -23,4 +23,4 @@ def build_error_message(errors, schema):
         "fields": fields
     }
 
-    return json.dumps(message)
+    return json.dumps(message)