WIP: Adding Artistic License 2.0 to the set of acceptable licenses

This MR adds the Artistic License 2.0 to the set of acceptable licenses. Unfortunately I could not find a good resource that compares the MIT license with the Artistic License in a detailed way.

This page contains a pretty nice overview though: https://www.toptal.com/open-source/developers-guide-to-open-source-licenses

This is a blocker for the integration of npm audit as DS analyzer.