WIP: wait a bit extra for stats

sometimes it's not getting anything

test/rest/stats.test.js

@@ -84,7 +84,7 @@ define(['shared_helper', 'chai'], function (helper, chai) {
       }
       await rest.channels.get('channel').publish('message', 'data');
       // ably.com documentation says "The most recent statistics are delayed by up to six seconds."
-      await new Promise((resolve) => setTimeout(resolve, 6000));
+      await new Promise((resolve) => setTimeout(resolve, 6000 + 4000));
 
       const stats = (await rest.stats({ end: Date.now(), unit: 'hour' })).items[0];