Automatically build sass and sass:icons after build

Signed-off-by: John Molakvoæ <skjnldsv@protonmail.com>

package.json

@@ -9,6 +9,7 @@
   },
   "scripts": {
     "build": "NODE_ENV=production webpack --progress --config webpack.prod.js",
+    "postbuild": "npm run sass && npm run sass:icons",
     "dev": "NODE_ENV=development webpack --progress --config webpack.dev.js",
     "watch": "NODE_ENV=development webpack --progress --watch --config webpack.dev.js",
     "lint": "eslint 'apps/*/src/**/*.{vue,js}' 'core/src/**/*.{vue,js}'",