app/views/application/_header.html.erb
<nav class="main-header">
<%= link_to t('.title'), root_path, class: 'main-header__title' %>
<ul class="main-header__navigation">
<li class="main-header__navigation-item">
<%= link_to t('.find_a_conference'), root_path, class: 'main-header__link' %>
</li>
<li class="main-header__navigation-item">
<%= link_to t('.log_in_with_twitter'), organizer_twitter_omniauth_authorize_path, class: 'main-header__link' %>
</li>
</ul>
</nav>