Hello I'm having some trouble with deploying a MERN app to heroku Here's my package.json:

{
  "name": "",
  "version": "1.0.0",
  "description": "basketball shot journal log",
  "main": "server.js",
  "scripts": {
    "client-install": "npm install --prefix client",
    "start": "node server.js",
    "server": "nodemon server.js",
    "client": "npm start --prefix client",
    "dev": "concurrently \"npm run server\" \"npm run client\"",
    "heroku-postbuild": "NPM_CONFIG_PRODUCTION=false npm install --prefix client &&  npm run build --prefix client"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.18.3",
    "concurrently": "^4.1.0",
    "express": "^4.16.4"
  }
}

But when I git push heroku master I get this error

`NPM_CONFIG_PRODUCTION=false npm install --prefix client &&  npm run build --prefix client`
remote: npm ERR! Exit status 254
remote: npm ERR! 
remote: npm ERR! Failed at the walking-bucket@1.0.0 heroku-postbuild script.

It seems I need a build script but I'm not sure exactly what it needs to look like. I was following a Traversy tutorial and he didn't seem to have one?

"build": "npm build server.js" Does that look close?