func changedPresence(slackApi gobot.SlackApi, presenceChange gobot.PresenceChange) {
user, err := slackApi.GetUser(presenceChange.User)
if err == nil {
fmt.Println(user.Name + " changed status to " + presenceChange.Presence)
}
}
func echoMessage(slackApi gobot.SlackApi, message gobot.Message) {
slackApi.PostMessage(message.Channel, message.Text)
}