Move data to json (#15)

- Move hard coded countries and operators into json files
- Parse files at init time
- Update all handlers to expect unicode/lists
- Update tests
I guess I'm still confused why .json is an advantage here. In three easy steps:
* rename .json to .py
* replace null with None
* give this list a value eg: countries = [...

You've got a Python file, you can remove the code that parses JSON, the module is smaller and faster.