Test fails to exit when nothing is added to the queue in a custom command

[justafish]

Seen in 0.9.20 (I unsuccessfully tried to run our tests on 1.0.4 but it had dependency issues and wasn't able to find our globals file)

This should reproduce it:

exports.command = function myCommand(callback) {
  const self = this;

  try {
    throw new Error('myerror');
  }
  catch(error) {
    this.assert.fail(error);
  }

  if (typeof callback === 'function') {
    callback.call(self);
  }
  return this;
};

Which will hang like this:

[Example Test] Test Suite
=============================

Running:  Test page
 ✖ Failed [fail]: (Error: myerror)
    at Object.installDrupal (/Users/justafish/Repos/drupal/core/tests/Drupal/Nightwatch/Commands/installDrupal.js:39:17)

^C

If I add this.pause(1);, then the tests fails and exits fine.

```[Example Test] Test Suite
=============================

Running:  Test page
 ✖ Failed [fail]: (Error: lol)
    at Object.installDrupal (/Users/justafish/Repos/drupal/core/tests/Drupal/Nightwatch/Commands/installDrupal.js:39:17)


FAILED:  1 assertions failed (941ms)

 _________________________________________________

 TEST FAILURE:  1 assertions failed, 0 passed. (1.927s)

 ✖ exampleTest

   - Test page (941ms)
   Failed [fail]: (Error: myerror)
       at Object.installDrupal (/Users/justafish/Repos/drupal/core/tests/Drupal/Nightwatch/Commands/installDrupal.js:39:17)

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[beatfactor]

Can you please re-try with v1.0.5?

[beatfactor]

Closing as due to lack of follow up.