File: app/Views/Include/header.html.twig

<div class="row header">
    <div class="header-logo col-md-4">
        <a href="http://symfony.com/">
            <img src="{{ asset('/img/assets/symfony/header-logo.svg') }}" alt="Symfony" class="img-responsive">
        </a>
    </div>
    <div class="log-in-out col-md-2" style="margin-top: 23px;">
        {% if app.user and is_granted('IS_AUTHENTICATED_FULLY') %}
            <a href="{{ path('logout') }}">{{ 'logout'|trans|capitalize }} </a>({{ app.user.username }})
        {% else %}
            <a href="{{ path('login') }}">{{ 'login'|trans|capitalize }}</a> /
            <a href="{{ path('registration') }}">{{ 'registration'|trans|capitalize }}</a>
        {% endif %}
    </div>
</div>