added dm channel support.

message.go

@@ -108,12 +108,7 @@ func (m *Message) Edit(content string) error {
 // Delete the message.
 func (m Message) Delete() error {
 	_, err := m.Client.Request("DELETE", "/channels/"+m.ChannelId+"/messages/"+m.Id, []byte{})
-
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }
 
 // Reply to the message.