Update readme

Fixin readme to reflect new always-on API (yay :fireworks: :dancer: :metal: ) cc @salsalabs

Closes #40

![stick-woo_zps5c1a47c7](https://cloud.githubusercontent.com/assets/700444/4328454/5e0c40e6-3f85-11e4-8167-1a6ed7f22c56.gif)