update Message struct for new fields, add IsSuperGroup to Chat struct

types.go

@@ -71,6 +71,11 @@ func (c *Chat) IsGroup() bool {
 	return c.Type == "group"
 }
 
+// IsSuperGroup returns true if the Chat is a supergroup conversation
+func (c *Chat) IsSuperGroup() bool {
+	return c.Type == "supergroup"
+}
+
 // IsChannel returns true if the Chat is a channel
 func (c *Chat) IsChannel() bool {
 	return c.Type == "channel"
@@ -101,6 +106,10 @@ type Message struct {
 	NewChatPhoto          []PhotoSize `json:"new_chat_photo"`
 	DeleteChatPhoto       bool        `json:"delete_chat_photo"`
 	GroupChatCreated      bool        `json:"group_chat_created"`
+	SuperGroupChatCreated bool        `json:"supergroup_chat_created"`
+	ChannelChatCreated    bool        `json:"channel_chat_created"`
+	MigrateToChatID       int         `json:"migrate_to_chat_id"`
+	MigrateFromChatID     int         `json:"migrate_from_chat_id"`
 }
 
 // Time converts the message timestamp into a Time.
@@ -110,7 +119,7 @@ func (m *Message) Time() time.Time {
 
 // IsGroup returns if the message was sent to a group.
 func (m *Message) IsGroup() bool {
-	return m.From.ID != m.Chat.ID
+	return m.Chat.IsGroup()
 }
 
 // IsCommand returns true if message starts from /