#Pinteresting - Pinterest Clone

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