-p added to mkdir to not fail if already exists

package.json

@@ -4,7 +4,7 @@
   "description": "Rawr, if you must refer to me this is how you may",
   "main": "app.js",
   "scripts": {
-    "postinstall": "mkdir ./dist",
+    "postinstall": "mkdir -p ./dist",
     "start": "concurrently npm:serve:*",
     "build": "concurrently npm:build:*",
     "serve:handlebars": "node app.js",