title: Facing issue in converting from gulp version 3 to gulp version 4
body: <p>In <strong>gulp version 3</strong>, my <code>help</code> gulp task defined as:</p>
  
  <pre><code>gulp.task('help', function() {
   var command = chalk.bold.green;
   console.log(command('gulp build-task') + ': runs certain build tasks');
  });
  
  gulp.task('default', ['help']);
  </code></pre>
  
  <p>I do the following to convert this to <strong>gulp version 4</strong>:</p>
  
  <pre><code>gulp.task('help', function() {
   var command = chalk.bold.green;
   console.log(command('gulp build-task') + ': runs certain build tasks');
  });
  
  gulp.task('default', gulp.series('help'));
  </code></pre>
  
  <p>On running <code>gulp</code>, I see the following <strong>error</strong>:</p>
  
  <pre><code>[01:58:01] The following tasks did not complete: default, help
  [01:58:01] Did you forget to signal async completion?
  </code></pre>
  
  <p>Also, I want the the <code>help</code> task to run first and then <code>default</code>. In my version 4 example, <code>default</code> runs first.</p>
  
  <p>Can someone please help me with this? Thank you!</p>