Promise support

[eddieajau]

I don't support you'd be interested in working on a version that supports returning a Promise (I'm happy to help if you are)? For example:

events.on('test', function (e) {
  // The next event listener will wait til this is done
  return new Promise((resolve) => {
    setTimeout(resolve, 1000);
  });
});

// Then either
events.emit('test', { data: 'data' })
  .catch(err => console.log('Oops:', err));

// Or
try {
  await events.emit('test', { data: 'data' });
}
catch (err) {
  console.log('Oops:', err)
}

Thanks in advance.

[ahultgren]

I think this makes sense. I don't have much time to work on OS projects nowadays though, so can't make any guarantees about when. Help is welcome.