title: WordPress phpunit test not found WP_UnitTestCase
body: <p>I have wordpress project running on my local. I use docker.
  I install phpunit using composer require phpunit/phpunit command. (Version is 8.5)
  Then I use scaffold command to create plugin test files. 
  docker-compose exec wp my-project-name wp scaffold plugin-tests sample-plugin (I have all files)</p>
  
  <p>Then I run following command but it didn't create tmp/ directory in my project. Instead it made directory here: C:\Users\Unknown\AppData\Local\Temp. 
  bin/install-wp-tests.sh wordpress_my root 'mypassword' localhost latest </p>
  
  <p>Now when I run following command, it gives following error.
  vendor/bin/phpunit --bootstrap ./vendor/autoload.php wp-content/plugins/sample-plugin/tests/test-sample.php</p>
  
  <blockquote>
    <p>Fatal error: Uncaught Error: Class 'WP_UnitTestCase' not found in C:\git\my-project\wp-content\plugins\sample-plugin\tests\test-sample.php:11
    Stack trace:</p>
  </blockquote>
  
  <p>I also followed first 4 steps from <a href="https://make.wordpress.org/core/handbook/testing/automated-testing/phpunit/" rel="nofollow noreferrer">https://make.wordpress.org/core/handbook/testing/automated-testing/phpunit/</a> but no luck.</p>
  
  <p>Also <a href="https://www.smashingmagazine.com/2017/12/automated-testing-wordpress-plugins-phpunit/" rel="nofollow noreferrer">https://www.smashingmagazine.com/2017/12/automated-testing-wordpress-plugins-phpunit/</a> but no luck</p>
  
  <p>Please help me!</p>