title: Keep getting error on Symfony after installing JsFormValidatorBundle
body: <p>After installing JsFormValidatorBundle, I keep getting the error bellow when I try to open my page on localhost. I installed the bundle following the instruction on <a href="https://github.com/formapro/JsFormValidatorBundle" rel="nofollow">https://github.com/formapro/JsFormValidatorBundle</a>, composer installed the bundle successfully. My Symfony version is the 2.8. And my composer is updated.</p>
  
  <blockquote>
    <p>InvalidArgumentException in FormPass.php line 59:
    Tagged form type extension must have the extended type configured using the extended_type/extended-type attribute, none was configured for the "fp_js_form_validator.extension" service.</p>
  </blockquote>
  
  <p>I tried to add this information at <code>app/config/services.yml</code>, but did not work:</p>
  
  <pre><code>fp_js_form_validator.extension:
      class: Fp\JsFormValidatorBundle\Form\Extension\FormExtension
      tags:
          - { name: form.type_extension, alias='form', extended_type: Symfony\Component\Form\Extension\Core\Type\FileType }
  </code></pre>
  
  <p>Thanks</p>