Spec compliance!

I added the last few bits remaining to get this fully todo-backend spec compliant.

I also took the liberty of setting it up running on a [heroku instance](http://todo-backend-webpy.herokuapp.com/), and [listing it](http://todo-backend.thepete.net/index.html#implementations) as a compliant implementation on the todo-backend website. 

If you'd like me to change the description just let me know, or send a [pull request](https://github.com/moredip/todo-backend-site/blob/master/public/index.html). If you'd like me to take down the heroku instance so you can have a canonical one managed by you and pointing to your repo then just let me know.