🎨 Add npm script

Author: nuintun

package.json

@@ -32,6 +32,7 @@
     "uglify-es": "^3.3.9"
   },
   "scripts": {
+    "prepublishOnly": "node rollup.js",
     "test": "mocha --timeout 6000 --check-leaks --reporter spec --bail --exit",
     "test-ci":
       "istanbul cover ./node_modules/mocha/bin/_mocha --report lcovonly -- --timeout 6000 --check-leaks --reporter spec --exit",