title: Unknown database type enum requested, Doctrine\DBAL\Platforms\MySQL57Platform may not support it. Symfony
body: <p>I created a fresh symfony4 project. Made user Entity using <code>php bin/console make:user</code>, then tried to migrate using <code>php bin/console make:migration</code>. But then the error pops up  </p>
  
  <blockquote>
    <p>In AbstractPlatform.php line 434:</p>
    
    <p>Unknown database type enum requested,
    Doctrine\DBAL\Platforms\MySQL57Platform may not support it.</p>
  </blockquote>
  
  <p>The strange thing is the User entity doesn't have any <code>enum</code> type rather it has a json column of roles, I suppose this is the reason. </p>
  
  <pre><code> /**
   * @ORM\Column(type="json")
   */
   private $roles = [];
  </code></pre>
  
  <p>I have seen some answers for the similar question for laravel, But don't know how to fix it in symfony4. </p>