title: Devise form rendered twice
body: <p>I follow devise tutorial. I edit the form same as the tutorial said and I see it rendered twice. </p>
  
  <p><a href="https://www.sitepoint.com/devise-authentication-in-depth/" rel="nofollow">https://www.sitepoint.com/devise-authentication-in-depth/</a></p>
  
  <p>I can't reply it. </p>
  
  <pre><code>&lt;% header "Sign Up" %&gt;
  
  &lt;%= form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f| %&gt;
    &lt;%= devise_error_messages! %&gt;
  
    &lt;div class="form-group"&gt;
      &lt;%= f.label :name %&gt;
      &lt;%= f.text_field :name, class: 'form-control' %&gt;
    &lt;/div&gt;
  
    &lt;div class="form-group"&gt;
      &lt;%= f.label :email %&gt;
      &lt;%= f.email_field :email, class: 'form-control' %&gt;
    &lt;/div&gt;
  
    &lt;div class="form-group"&gt;
      &lt;%= f.label :password %&gt;
      &lt;%= f.password_field :password, autocomplete: "off", class: 'form-control' %&gt;
      &lt;% if @validatable %&gt;
        &lt;span class="help-block"&gt;&lt;%= @minimum_password_length %&gt; characters minimum&lt;/span&gt;
      &lt;% end %&gt;
    &lt;/div&gt;
  
    &lt;div class="form-group"&gt;
      &lt;%= f.label :password_confirmation %&gt;
      &lt;%= f.password_field :password_confirmation, autocomplete: "off", class: 'form-control' %&gt;
    &lt;/div&gt;
  
    &lt;%= f.submit "Sign up", class: 'btn btn-primary' %&gt;
  &lt;% end %&gt;
  
  &lt;%= render "devise/shared/links" %&gt;
  </code></pre>
  
  <p>Here is my view. I didn't mess with controller.</p>