add heroku readme stuff

### What is the problem / feature ?

There was no info about heroku in the readme

### How did it get fixed / implemented ?

Added heroku info to the readme

### How can someone test / see it ?

View the readme

*Here is a cute baby animal picture for your troubles...*

![tumblr_lpkqz74yfx1qi4ucgo1_500](https://f.cloud.github.com/assets/824194/2492445/dce6cd86-b22d-11e3-8e01-0b57c18f0fb2.jpg)