code: function (src, output) {
      return new Elixir.GulpPaths()
          .src(src, config.get('assets.js.folder'))
          .output(output || config.get('public.js.outputFolder'), 'bundle.js');
  }
docs: Prep the Gulp src and output paths.
  
  @param  {String|Array} src
  @param  {String|null}  output
  @return {GulpPaths}