Merge branch 'rs-update-uglifier' into 'master'

Update uglifier to ~> 2.7.2

Fixes a security vulnerability:

- https://github.com/lautis/uglifier/pull/86
- https://github.com/mishoo/UglifyJS2/issues/751
- https://zyan.scripts.mit.edu/blog/backdooring-js/

See merge request !1590