title: What is .phpunit.result.cache
body: <p>When I run tests with <strong>PhpUnit</strong> on a new package I'm creating for Laravel, it generates the file <code>.phpunit.result.cache</code>.  </p>
  
  <p>What to do with that? Do I add it to my <code>.gitignore</code> file or not?</p>
  
  <p>I'm using PHPUnit 8.0.4</p>