Move _typing to text-based channels

src/structures/Channel.js

@@ -20,7 +20,6 @@ class Channel {
      */
     this.type = null;
 
-    this._typing = new Map();
     if (data) this.setup(data);
   }
 

src/structures/DMChannel.js

@@ -25,6 +25,7 @@ class DMChannel extends Channel {
 
     this.type = 'dm';
     this.lastMessageID = data.last_message_id;
+    this._typing = new Map();
   }
 
   /**

src/structures/GroupDMChannel.js

@@ -72,9 +72,9 @@ class GroupDMChannel extends Channel {
       }
     }
 
-    this.id = data.id;
     this.type = 'group';
     this.lastMessageID = data.last_message_id;
+    this._typing = new Map();
   }
 
   equals(other) {

src/structures/TextChannel.js

@@ -22,13 +22,9 @@ class TextChannel extends GuildChannel {
      */
     this.topic = data.topic;
 
-    /**
-     * The ID of the last message in the channel, if one was sent.
-     * @type {?string}
-     */
-    this.lastMessageID = data.last_message_id;
-
     this.type = 'text';
+    this.lastMessageID = data.last_message_id;
+    this._typing = new Map();
   }
 
   sendMessage() {