Ejecting crashes if no devDependencies exists in package.json

Created by: geelen

Just hit a bug where yarn eject (or npm run eject) fails with the following message:

TypeError: Cannot read property 'react-scripts' of undefined
    at inquirer.prompt.then.answer (node_modules/react-scripts/scripts/eject.js:149:36)
    at <anonymous>

Here's the line in question. I had moved all my devDependencies to dependencies in order for Heroku to run then in a postinstall step (more info here) and so the eject was exploding on this line. To fix, all I needed to do was:

   "version": "0.1.0",
   "private": true,
+  "devDependencies": {},
   "dependencies": {
     "react": "^15.5.4",
     "react-dom": "^15.5.4",
     "react-scripts": "^1.0.7"
   },

Not necessarily something that needs fixing, but if anyone is googling the exact error message above then this issue will hopefully guide them towards the same fix!