Add licenses plugin

[lowlighter]

Add a new 📜 licenses plugin, targetted for repositories' metrics to inform about licenses compliancy, permissions, limitations and conditions based on current license and licenses from used dependencies.

• Base metrics will display a few stats (nb of dependencies, known licenses and unknown licenses)
• plugin_licenses_ratio lets you display total ratio of each used licenses
• plugin_licenses_legal lets you display which permissions, limitations and conditions are implied by current license and licenses from used dependencies (inherited limitations and conditions will be indicated with a different icon while conflicting permissions will be removed)

It use github/licensed to detect licenses.

Examples output:

Permissions, limitations and conditions:

Ratio:

Both can be of course combined in a single SVG output.

Disclaimer: This is not legal advice. Use at your own risk

[Milo123459]

I'm confused, this is just going to tell you the license you use the most?

[lowlighter]

What you mention is already available in user's metrics 🙂

This one is targetted exclusively for repositories metrics to display licenses compliancy, permissions, limitations and conditions (a bit like what is currently displayed by GitHub when going on a LICENSE page, but metrics will also try to analyze dependencies licenses).

It's still not finished yet as I'm waiting for github/licensed v2.14.4 release, but it'll probably end up looking like this :

As you can see, there's legal rights from "base" license but also "inherited limitations" in this case, which would preventing patenting the code as a whole (i.e. including dependencies) since it is explicitely forbidden.

But it's just for informative purposes though, it cannot be used as legal advice 🙂

[Milo123459]

That PR is merged

[lowlighter]

@jonabc
Thought you might be interested seeing end result 🙂 :

There is still room for improvements, but I'll probably check again in the future.
Seems that GitHub is missing some "common" licenses in their GraphQL API though (like ISC license for example)

Thanks again for your work!

[jonabc]

very cool, thanks for the ping!