fix(Guild): memberCount not decrementing when an uncached member leaves

This leads to GuildMemberStore#_fetchMany to always reject
because it expects more member than possible.

Also no longer call the GuildMemberRemove handler locally
to not decrement twice.

src/structures/GuildMember.js

@@ -526,12 +526,7 @@ class GuildMember extends Base {
    */
   kick(reason) {
     return this.client.api.guilds(this.guild.id).members(this.user.id).delete({ reason })
-      .then(() =>
-        this.client.actions.GuildMemberRemove.handle({
-          guild_id: this.guild.id,
-          user: this.user,
-        }).member
-      );
+      .then(() => this);
   }
 
   /**