Update README

Author: Jake Hartnell

README.md

@@ -3,6 +3,8 @@
 Make sure you have Node.js and git installed on your pi.
 
 ```bash
+sudo apt-get update
+sudo apt-get install wiringpi
 git clone https://github.com/CommonGarden/CompostBrewer
 cd CompostBrewer/driver
 npm install