title: Laravel nullable validation rule not working
body: <p>I recently upgraded to laravel 5.4 (from 5.2) to make use of the <code>nullable</code> validation rule.</p>
  
  <p>I have a field <code>act_post_code</code> which can be either an <code>integer</code> OR <code>null</code>. So I provided the following rule in my <code>Request</code> class.</p>
  
  <pre><code>'act_post_code' =&gt; 'integer|nullable'
  </code></pre>
  
  <p>In Postman using <code>form-data</code>, I provide a key = <code>act_post_code</code> with its value = <code>null</code>.</p>
  
  <p>The response I get is the following:</p>
  
  <pre><code>{
      "act_post_code": [
          "The act post code must be an integer."
      ]
  }
  </code></pre>