i have already tried following solution but it is not working.
sudo forever start -c "npm start" ./
and package.json file is something like this, look at the start command: (this is not full package.json)
"name": "angular2-quickstart",
  "version": "1.0.0",
  "scripts": {
    "lite": "lite-server",
    "gulp": "gulp",
    "start": "concurrent \"npm run gulp\" \"npm run lite\" ",
    "postinstall": "typings install",
    "tsc": "tsc",
    "tsc:w": "tsc -w",
    "typings": "typings"
  },
 
     
     
    