title: Bull without Redis for queue management
body: <p>Is it possible to use Bull (for job management) without using Redis?</p>
  <p>My code:</p>
  <pre class="lang-js prettyprint-override"><code>@Injectable()
  export class MailService {
      private queue: Bull.Queue;
      private readonly queueName = 'mail';
  
      constructor() {
          this.queue = new Bull(this.queueName)
      }
  
      addTaskToQueue() {
          this.queue.process('send_mail',
              async (job: Bull.Job, done: Bull.DoneCallback) =&gt; {
                  console.log('Send mail!');
                  console.log(JSON.stringify(job.data));
  
                  done();
              })
      }
  
      async send(year: number, month: number) {
          try{
              await this.queue.add('send_mail', {
                  year,
                  month
              });
              console.log('done');
          } catch(err){
              console.log(err);
          }
  
      }
  }
  </code></pre>
  <p>Upon running, my console trew this error:</p>
  <pre><code>{ Error: connect ECONNREFUSED 127.0.0.1:6379
      at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1107:14)
    errno: 'ECONNREFUSED',
    code: 'ECONNREFUSED',
    syscall: 'connect',
    address: '127.0.0.1',
    port: 6379 }
  </code></pre>