Use authentication from Scalingo command line tool

[archiloque]

It would be nice it the gem could rely on the credentials created by the command line tool, since there is already a token available in the JSON file.

It would makes the configuration simpler for scripts to be run on developers' machines.

[ksol]

Hello and thanks for the suggestion! This could indeed ease up scripting, and it should not be too complicated to set up.

We'll keep it in mind!