get rid of duplicate json calls

[aktau]

Well, you asked for it in your readme:

json_data, err := json.Marshal(message)
if err == nil {
    websocket.Message.Send(wsc.socket, string(json_data))
}

Could become:

websocket.JSON.Send(wsc.socket, message)

Because the go.net websocket implementation has a built-in JSON codec (which uses json.Marshal under the hood, of course). So that will make your code a bit more DRY.

Also you should check for errors:

if err := websocket.JSON.Send(wsc.socket, message); err != nil {
    log.Println("wsconnection: error, could not send json message, ", err)
    // or do something else if you want...
}