[Suggestion] Disabling displaying JS Uglify Warnings

[marbor3]

There are quite some warnings while uglifying main.js file - most if not all from 3rd party libs.

Maybe it's a good idea to disable them by adding compress options:

new webpack.optimize.UglifyJsPlugin({
    mangle: {
        'keep_fnames': true
    },
    compress: {
        warnings: false
    }
})

[backflip]

https://github.com/unic/estatico-nou/ will introduce different log levels. As an example you can run the html task with different envs:

• $ NODE_DEBUG=estatico-handlebars npm run gulp html
• $ NODE_DEBUG=estatico-handlebars-extended npm run gulp html

However, I'm evaluating whether we can simplify this in https://github.com/unic/estatico-nou/issues/12