Added build script

package.json

@@ -56,6 +56,7 @@
     ],
     "jsdelivr": "dist/mailymaily-min.js",
     "scripts": {
-        "lint": "eslint ./src/js/mailymaily.js"
+        "lint": "eslint ./src/js/mailymaily.js",
+        "build": "gulp"
     }
 }