Trying to do this: new webpack.optimize.UglifyJsPlugin({ comments: false })

Setting will be overwritten because of this:
https://github.com/webpack/webpack/blob/master/lib/optimize/UglifyJsPlugin.js#L79

Other reference:
https://github.com/mishoo/UglifyJS2/blob/master/lib/output.js#L62