Pinterest Clone App

User stories:

1. As an unauthenticated user, I can login with GitHub.
2. As an authenticated user, I can link to images.
3. As an authenticated user, I can delete images that I've linked to.
4. As an authenticated user, I can see a Pinterest-style wall of all the images I've linked to.
5. As an unauthenticated user, I can browse other users' walls of images.
6. As an authenticated user, if I upload an image that is broken, it will be replaced by a placeholder image.

You can view the live demo here: https://piccisy.herokuapp.com