API doesnt allow to know when redis connection is ready

Created by: pmvrmc

When creating a new queue, there is no ready event for the redis connection, so we don't know if it is ready or not. Digging through the code it looked to me that bull is only emitting redis 'error' event and not 'ready', 'reconnecting', etc.

Also the queue.isReady() will always resolve fine even if there is no connection ready:

const queue = new Queue('queue');
queue.isReady().then(() => {
  console.log('this is always print even if redis is down');
});