Fix #5 Could not build with a root account

package.json

@@ -22,6 +22,6 @@
     "underscore": "1.8.3"
   },
   "scripts": {
-    "postinstall": "node \"node_modules/bower/bin/bower\" install && node \"node_modules/brunch/bin/brunch\" build"
+    "postinstall": "node \"node_modules/bower/bin/bower\" install --allow-root && node \"node_modules/brunch/bin/brunch\" build"
   }
 }