add y coordinate to player position in updatePlayer task

[MeerBiene]

closes #199

[MeerBiene]

When you have the time to review this, I've thought about the /players.json request and want to make the following suggestion: How about we keep an internal map for the playerdata and the request to /players.json returns this map instead of the json file. I can imagine this becoming a problem with this many I/O operations. Let me know what you think