title: Parsley custom validator is not working
body: <p>so I have this custom validator which for testing reasons should always return false:</p>
  
  <pre><code>$(document).ready(function(){   
  
    $('#new_user').parsley({
      validators: {
        urlasemail: function () {
          return {
            validate: function ( val, emailField ) {
              alert('good');
              return false;
            }
          };
        }
      }
    });
  
  });
  </code></pre>
  
  <p>And the form field looks like this:</p>
  
  <pre><code>&lt;input class="string url required" id="something" name="website" parsley-error-message="" parsley-trigger="keyup" parsley-urlasemail="nothing" placeholder="mywebsite.com" size="50" type="text"&gt;
  </code></pre>
  
  <p>When I don't specify a priority for the validator as above then I get a console log saying that validator "urlasemail" has default priority.</p>
  
  <p>So for some reason it looks like the JS is fine but it just doesn't want to validate...</p>