title: How to custom error messages
body: <p>Hi everyone and thanks for your help.
  I'll like to custom error messages for validation <strong>and</strong> <em>eventually to create different version for each language</em>, <strong>it's possible ?</strong></p>
  
  <p>Here my code in his actually state.</p>
  
  <pre><code>namespace App;
  
  use Respect\Validation\Exceptions\ValidationException;
  use Respect\Validation\Exceptions\NestedValidationException;
  use Respect\Validation\Validator as v;
  
  class Validator {
  
      private $messages = [
          'lastname',
          'firstname',
          'phone',
          'email',
          'message'
      ];
  
      //other functions and declarations of my class.
  
      private function validationData() {
          $rule = null;
  
          switch ($this-&gt;page) {
              case 'contact';
                  $rule = v::key('lastname', v::notEmpty()
                                              -&gt;alpha("-'"))
                           -&gt;key('firstname', v::optional(v::alpha("-'")))
                           -&gt;key('phone', v::optional(v::phone()))
                           -&gt;key('email', v::email())
                           -&gt;key('message', v::optional(v::length(5, 500)));
                  break;
              default;
                  break;
          }
          try {
              $rule-&gt;assert($this-&gt;data);
          } catch (ValidationException $exception) {
              var_dump($exception-&gt;findMessages($this-&gt;messages));
          }            
       }
   }
  </code></pre>
  
  <p>It returns me that:</p>
  
  <pre><code>array(5) {
  ["lastname"]=&gt; string(51) "lastname must contain only letters (a-z) and ""-'"""
  ["firstname"]=&gt; string(0) ""
  ["phone"]=&gt; string(38) "phone must be a valid telephone number"
  ["email"]=&gt; string(25) "email must be valid email"
  ["message"]=&gt; string(44) "message must have a length between 5 and 500"
  }
  </code></pre>
  
  <p>I need to keep this structure of my result of validation. Because I need field's names for could to display them at client side.</p>
  
  <p>Thanks again,</p>