Added Procfile to simplify debuging

￼This simple Procfile allows you to run listener, replay and 2 http servers (for listening and replaying) with 1 command. And it will show you nice colorized output for each process.

![image](https://f.cloud.github.com/assets/14009/1304158/6fac4bf2-3176-11e3-96ea-afa8f823788f.png)

Very good for live debugging. 

To trigger listener just do: `curl localhost:8000`