TRACKING: third party licensing

[hansl]

Some of our direct and indirect dependencies are not using licenses that are approved by Google, so we need to do something about it. We have three options for each of those: ask authors to relicense, reimplement ourselves, or stop using the dependency.

Here's a (maybe incomplete) list:

• uc.micro - WTFPL (from markdown-it). markdown-it might have replacements that are available, so I'll look for those.
• sourcemap-istanbul-instrumenter-loader - WTFPL. We should probably contact the author for this one. Might not be needed.
• jsonify - Public Domain (not a valid license, from ember-cli-preprocess-registry/broccoli-clean-css/json-stable-stringify). We don't need the preprocess-registry and will probably get rid of it.

Other point to consider this completed:

• make a test to check licenses from package.json of every dependencies on Travis.

We might need to make separate issues to track some of those individually.

cc @IgorMinar @naomiblack

[hansl]

Shoutout to Robert Spier who found those!

[JohannesRudolph]

Alternative reading: Google's legal team should work on approving the WTFPL :-)

[filipesilva]

sourcemap-istanbul-instrumenter-loader is the only one missing now.

There seems to be a yarn tool to list licences, we should add a test that uses it.

[filipesilva]

The sourcemap-istanbul-instrumenter-loader author at webpack-contrib/istanbul-instrumenter-loader#39 seems to be ok with changing to MIT.