Added the express_region_code to the config, fedex now throws errors if you don't set it.

Author: jcartmell

fedex/config.py

@@ -55,6 +55,8 @@ def __init__(self, key, password, account_number=None, meter_number=None,
         """@ivar: Web services meter number."""
         self.integrator_id = integrator_id
         """@ivar: Web services integrator ID."""
+        self.express_region_code = express_region_code
+        """@icar: Web services ExpressRegionCode"""
         self.use_test_server = use_test_server
         """@ivar: When True, point to the test server."""