Removed onEvent handler

With the recent change to the OnEvent event now always executing
insted of only on error we don't want this printing out every
single event.  A different way to handle unknown events will be
added in the wsapi.go code.

discord.go

@@ -225,7 +225,6 @@ func (s *Session) initialize() {
 	s.handlers = map[interface{}][]reflect.Value{}
 	s.handlersMu.Unlock()
 
-	s.AddHandler(s.onEvent)
 	s.AddHandler(s.onReady)
 	s.AddHandler(s.onVoiceServerUpdate)
 	s.AddHandler(s.onVoiceStateUpdate)
@@ -236,8 +235,3 @@ func (s *Session) initialize() {
 func (s *Session) onEvent(se *Session, e *Event) {
 	printEvent(e)
 }
-
-// onReady handles the ready event.
-func (s *Session) onReady(se *Session, r *Ready) {
-	go s.heartbeat(s.wsConn, s.listening, r.HeartbeatInterval)
-}