added npm run build

Tools/Gulp/package.json

@@ -9,6 +9,7 @@
     "readme": "https://github.com/BabylonJS/Babylon.js/edit/master/readme.md",
     "license": "(Apache-2.0)",
     "scripts": {
-        "install": "cd ../../ && npm install && cd Playground/ && npm install && cd ../Viewer && npm install && cd ../Tools/Gulp/"
+        "install": "cd ../../ && npm install && cd Playground/ && npm install && cd ../Viewer && npm install && cd ../Tools/Gulp/",
+        "build": "gulp --max-old-space-size=8192"
     }
-}
+}