title: Render a template instead a success_url in form_valid with FormView django
body: <p>As the title says: I need to render a template after submitting a form, this form is handled with <code>FormView</code> with the method <code>form_valid</code>. With the method <code>post</code>, I can render a template after submitting it but maybe with <code>form_valid</code>, I can do it in the cleanest way.</p>
  
  <p>How can I do it?</p>