Change version number to string to fix handshake

[Skillkiller]

The previous websocket handshake message is not valid because the version number was transmitted as a number: {"type":"Handshake","version":0.2}

Response: {"type": "InvalidRequest","msg": "Invalid Request - please have a look at the docs"}

Now the version number is transmitted as a string: {"type":"Handshake","version":"0.2"}

Response: {"type":"UpdateVersion","version":"0.2"}