old_contents: 'use strict';
  
  let TelegramBot = require('node-telegram-bot-api');
  var Firebase = require("firebase");
  let request = require('request-promise');
  
  let TelegramBotToken = process.env.TELEGRAM_BOT_TOKEN;
  let telegramBot = new TelegramBot(TelegramBotToken, { polling: true });
  
  let registeredUsers = [], currentTopStory;
  
  function getTopStory(){
      return request('https://hacker-news.firebaseio.com/v0/topstories.json').then(data => 
          request('https://hacker-news.firebaseio.com/v0/item/' + JSON.parse(data)[0] + '.json?print=pretty')
      );
  };
  
  function pushTopStory(story){
      registeredUsers.forEach(user => telegramBot.sendMessage(user, story.title + ' - ' + story.url));
      currentTopStory = story.id;
  }
  
  setInterval(() => {
       getTopStory().then(data => {
          data = JSON.parse(data);
  
          if(data.id !== currentTopStory){
              pushTopStory(data);
          }
       });
  }, 10000);
  
  telegramBot.onText(/\/start/, msg => {
      registeredUsers.push(msg.from.id);
      telegramBot.sendMessage(msg.from.id, 'Thanks, you\'re now registered, you\'ll get a message when the top story changes!');
  });
  
new_contents: 'use strict';
  
  let TelegramBot = require('node-telegram-bot-api');
  let request = require('request-promise');
  
  let TelegramBotToken = process.env.TELEGRAM_BOT_TOKEN;
  let telegramBot = new TelegramBot(TelegramBotToken, { polling: true });
  
  let registeredUsers = [], currentTopStory;
  
  function getTopStory(){
      return request('https://hacker-news.firebaseio.com/v0/topstories.json').then(data => 
          request('https://hacker-news.firebaseio.com/v0/item/' + JSON.parse(data)[0] + '.json?print=pretty')
      );
  };
  
  function pushTopStory(story){
      registeredUsers.forEach(user => telegramBot.sendMessage(user, story.title + ' - ' + story.url));
      currentTopStory = story.id;
  }
  
  setInterval(() => {
       getTopStory().then(data => {
          data = JSON.parse(data);
  
          if(data.id !== currentTopStory){
              pushTopStory(data);
          }
       });
  }, 10000);
  
  telegramBot.onText(/\/start/, msg => {
      registeredUsers.push(msg.from.id);
      telegramBot.sendMessage(msg.from.id, 'Thanks, you\'re now registered, you\'ll get a message when the top story changes!');
  });
  
subject: Remove Firebase dependency