Fix long-polling

lib/poll.js

@@ -1,19 +1,10 @@
 export default function poll(bot) {
   return bot.api.getUpdates(bot.update).then(response => {
-    const again = wait(bot.update.timeout * 1000, bot).then(poll);
     if (!response.result.length) {
-      return again;
+      return poll(bot);
     }
     bot.emit('update', response.result);
 
-    return again;
+    return poll(bot);
   });
 }
-
-const wait = (miliseconds, value) => {
-  return new Promise(resolve => {
-    setTimeout(() => {
-      resolve(value);
-    }, miliseconds);
-  });
-};