* add support for 3.5 api
* removed "unused" import by accident
* Hardcoded values
Appearantly TG decided to change the size of a send image (again)
* test_official
* Improve coverage
* Finishing up
* spelling error
* pytest fixed tot < than 3.3 for python 3.3 support
* flake8
* rollback requirements
* as per CR
* object for provider_data
Make it possible to send an object that will be json-serialized for send_invoice + tests
* shorten error message
* using string_types
