Remove unused methods

message.go

@@ -8,10 +8,6 @@ type ChatMessage struct {
 	MessageType string `json:"type"`
 }
 
-func (s *ChatMessage) AsJson() string {
-	return s.Author + " says " + s.Body
-}
-
 func (s *ChatMessage) String() string {
 	return s.Author + " says " + s.Body
 }
@@ -19,7 +15,3 @@ func (s *ChatMessage) String() string {
 type PingMessage struct {
 	MessageType string `json:"type"`
 }
-
-func (self *PingMessage) AsJson() string {
-	return "{type: \"PING\"}"
-}