WIP - Puck.js reading CSC (cycling speed cadence) BLE sensor to replace bike computer head unit with Puck.js or (later) Pixl.js

@kierankay, hat's a tough task you take onto you... the way that Arduino works - polling loop - versus Espruino - interrupt driven - puts itself in way of adapting this code. Furthermore, check on the implementation of Promises in Arduino world. Depending what the adafruit libs give you (setting some flags on filtered reception of data and buffer thereof) and availability of a lib or your on implementation of Promises you should be able to lean on the main line and structure of the Espruino code...