Choosealicense-cli

- update to latest github api
- drop python 3.3 support and add 3.6 support

- show version info: -v -> -V
- python 3.5 support
- wheel support
- refactor some code
- add code coverage, style check when running the tests

- better exception handle
- add support for python 3
- add test

- feature supported:
- can list all the license
- can show the info of the license
- show the context for the license template
- generate a license