title: error with PUGXMultiUserBundle
body: <p>i installed PUGXMultiUserBundle using this documentation <strong><a href="https://github.com/PUGX/PUGXMultiUserBundle/blob/master/Resources/doc/index.md" rel="nofollow">https://github.com/PUGX/PUGXMultiUserBundle/blob/master/Resources/doc/index.md</a></strong>
  i have two isues : 
      first i don't know where i should put the User Manager</p>
  
  <pre><code>$discriminator = $this-&gt;container-&gt;get('pugx_user.manager.user_discriminator');
  $discriminator-&gt;setClass('Acme\UserBundle\Entity\UserOne');
  
  $userManager = $this-&gt;container-&gt;get('pugx_user_manager');
  
  $userOne = $userManager-&gt;createUser();
  
  $userOne-&gt;setUsername('admin');
  $userOne-&gt;setEmail('admin@mail.com');
  $userOne-&gt;setPlainPassword('123456');
  $userOne-&gt;setEnabled(true);
  
  $userManager-&gt;updateUser($userOne, true);
  </code></pre>
  
  <p>and other thing when i try to run register page , i have this error :</p>
  
  <pre><code>UserDiscriminator, error getting form type : "MyApp\UserBundle\Form\Type\RegistrationUserOneFormType" not found
  </code></pre>
  
  <p>Thank you for yourhelp</p>