Bump uglify-js from 3.5.15 to 3.6.0 (#541)
Bump uglify-js from 3.5.15 to 3.6.0 (#541)

Bumps [uglify-js](https://github.com/mishoo/UglifyJS2) from 3.5.15 to 3.6.0.
- [Release notes](https://github.com/mishoo/UglifyJS2/releases)
- [Commits](https://github.com/mishoo/UglifyJS2/compare/v3.5.15...v3.6.0)
thisconnect/tools,thisconnect/tools