added link to presentation slides
added link to presentation slides

idcrook/rpi-iot-demo-2017,idcrook/rpi-iot-demo-2017,idcrook/rpi-iot-demo-2017,idcrook/rpi-iot-demo-2017,idcrook/rpi-iot-demo-2017,idcrook/rpi-iot-demo-2017