title: error running rails -server, receiving error: yarn: error: no such option: --integrity
body: <p>I am working in Rails 6.0.3.4 and Ruby 2.7.1 and when I run <code>rails -s</code>, I get the following error in the terminal:</p>
  <pre><code>Usage: yarn [options]
  
  yarn: error: no such option: --integrity
  
  
  ========================================
    Your Yarn packages are out of date!
    Please run `yarn install --check-files` to update.
  ========================================
  
  
  To disable this check, please change `check_yarn_integrity`
  to `false` in your webpacker config file (config/webpacker.yml).
  </code></pre>
  <p>When I run <code>yarn install --check-files</code>, I receive the following error:</p>
  <pre><code>yarn: error: no such option: --check-files 
  </code></pre>
  <p>And I do have check_yarn_integrity set to false in webpacker.yml.</p>