Change license to MIT and update package.json

Adding information to `package.json` to drive the landing page at http://hackademy2013.dyn.io. Please send back a pull request to update any information.

Also adding LICENSE.txt, containing MIT license attribution requirements and disclaimer.

To add a real thumbnail to your name, create a [Gravatar](http://en.gravatar.com) profile with your email address in the contributors section of `package.json` (or add the email address to an existing profile).