vlv-search/web/views/partials/auth.erb

<% if signed_in? %>
  <form class="auth" method="POST" action="/logout">
    <p class="auth__copy">
      Logged in as <span class="auth__username"><%= current_user %></span>
    </p>
    <input type="submit" class="auth__logout btn btn--small" value="Logout">
  </form>
<% end %>