- Added a unit test which tests the encoding - So far it just checks that the version is encoded correctly
- `getByte()` now tacks on the calculated first byte - `getBytes()` encodes the rquest/response code now as well
- Defined `CoapPacket` to represent a CoAP packet - Added the required fields - Constructor sets the version to `1` (the only version available) - `getBytes()` no encodes the first byte of the CoAP header (versio, type and token length)
- Added the codes for messages - These are 8-bits