code: function concatPackages (packages, outDir, minified) {
    if (! outDir) outDir = path.join('.', 'build');
  
    if (!fs.existsSync(outDir)) fs.mkdirSync(outDir);
    var jsFileName = path.join(outDir, 'build.js');
    if (fs.existsSync(jsFileName)){
      fs.truncateSync(jsFileName, 0);
    }
    var cssFileName = path.join(outDir, 'build.css');
    if (fs.existsSync(cssFileName)){
      fs.truncateSync(cssFileName, 0);
    }
    _.each(packages, function (pack, i, l) {
      concatPackage(pack, outDir, minified);
    });
  }
docs: concatPackages: concatenate a list of packages ('packages'). 'outDir' is the output directory, 'minified' is whether or not to include minified files.