title: Lumen first install - ReflectionException: Class redis does not exist
body: <p>I am playing around with Lumen, I installed it via Lumen installer. After I do <code>composer install</code>, I try to use <code>artisan</code> but it throws the following error: </p>
  
  <pre><code>ReflectionException: Class redis does not exist in Container.php on line 752
  </code></pre>
  
  <p>My composer.json:</p>
  
  <pre><code>"require": {
          "php": "&gt;=7",
          "ext-pdo_pgsql": "*",
          "ext-soap": "*",
          "guzzlehttp/guzzle": "^6.3",
          "laravel/lumen-framework": "5.5.*",
          "laravel/tinker": "^1.0",
          "vlucas/phpdotenv": "~2.2"
      },
      "require-dev": {
          "barryvdh/laravel-ide-helper": "^2.4",
          "doctrine/dbal": "^2.5"
      },
  </code></pre>
  
  <p>Thanks in advance.</p>