anchor.diff:        <div class="container">
           <!-- Brand and toggle get grouped for better mobile display -->
           <div class="navbar-header">
  -          <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-ex1-collapse">
  -            <span class="sr-only">Toggle navigation</span>
  +          <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
  +            <span class="icon-bar"></span>
  +            <span class="icon-bar"></span>
  +            <span class="icon-bar"></span>
             </button>
             <a class="navbar-brand" href="<%= root_path %>">Gandalf</a>
           </div>
  
positive.code: 
      <!-- Main jumbotron for a primary marketing message or call to action -->
      <div class="container">
        <%= render partial: 'flash' %>
        <%= yield %>
      </div>
  
      <hr>
  
negative.code:                 </p>
                </li>
                <li>
                  <p class="navbar-text">
                    <%= link_to "Logout", destroy_user_session_path(current_user), method: :delete %>
                  </p>
                </li>
              <% else %>
                <li>
                  <p class="navbar-text">
                    <%= link_to "Login", new_user_session_path %>
                  </p>
                </li>
              <% end %>
            </ul>
  