Add python 3.4 to travis CI configuration.
Merge pull request #71 from Shopify/python3-travis

Add python 3.4 to travis CI configuration.
Add format setter and getter to CarrierService resource.

Otherwise python will fallback on the class variable that pyactiveresource
defines.
Add format setter and getter to FulfillmentService resource.
Merge pull request #70 from Shopify/carrier-service-format

Add format setter and getter to CarrierService resource.
Release v2.1.0
Merge https://github.com/Shopify/shopify_python_api