fix(Guild): remove member's voice state on guildMemberRemove

fixes #2430

src/client/actions/GuildMemberRemove.js

@@ -10,6 +10,7 @@ class GuildMemberRemoveAction extends Action {
       member = guild.members.get(data.user.id);
       guild.memberCount--;
       if (member) {
+        guild.voiceStates.delete(member.id);
         guild.members.remove(member.id);
         if (client.status === Status.READY) client.emit(Events.GUILD_MEMBER_REMOVE, member);
       }

src/structures/Guild.js

@@ -1033,6 +1033,15 @@ class VoiceStateCollection extends Collection {
     }
     super.set(id, voiceState);
   }
+
+  delete(id) {
+    const voiceState = this.get(id);
+    if (voiceState && voiceState.channel_id) {
+      const channel = this.guild.channels.get(voiceState.channel_id);
+      if (channel) channel.members.delete(id);
+    }
+    return super.delete(id);
+  }
 }
 
 module.exports = Guild;