Initial add of the shipping module
Adding base Accept code
Initial support for generating labels
- Add isset checks so that not everything is required to be there in the stdClass.
- Add a utilities class to ease the building of the XML request.
- Add a basic rate API class
- Add support for getting individual service rates.
- Add unit tests for rating API
Merge pull request #3 from Limelyte/shipping-and-rates

Shipping and rates