Build a full stack JavaScript app that implements the following User Stories:
- I can pass a URL as a parameter and I will receive a shortened URL in the JSON response.
- If I pass an invalid URL that doesn't follow the valid http://www.example.com format, the JSON response will contain an error instead.
- When I visit that shortened URL, it will redirect me to my original link.
- node.js
- heroku
- github
- atom