Update Travis CI configuration, update the license

1.2.6

Update license

Extend Travis configuration

1.2.5

Extend the travis config

Better Readme file

1.2.4

Better Readme

Add authorization_code request to the client

1.2.3

Add authorization_code request to the client

Direct support of json_encoded strings in _operate function

1.2.2

Allow to transfer string as data for api call

Better code structure

1.2.1

Better code structure