Merge branch 'master' into IR
Read pin state from IR

- Basic read pin functionality for left and right IR sensor
Ultrasonic Dev Basic

NewPing lib used for ultrasonic. Basic sonic read function added for
testing.

Bug:
- Randomly outputs 0 while testing to print when distance <20cm
Added Zumo libraries

Created libraries folder with required files to run motors and sensors.
Pin changes and added documentation

- Changed pin allocations for sensors to ones not used my motors etc.
- Added libraries and documentation for shield and compass
Merge branch 'SensorDev'