Fix HTML validation issue

source/_partials/navbar.html.twig

@@ -11,7 +11,7 @@
         </div>
 
         <div id="navbar" class="collapse navbar-collapse">
-            <ul class="nav navbar-nav" role="navigation">
+            <ul class="nav navbar-nav">
                 <li{% if page.nav == 'about' %} class="active"{% endif %}><a href="{{ site.url }}">About</a></li>
                 {% for item in [ 'work', 'services', 'talks', 'blog', 'contact' ] %}
                     <li{% if page.nav == item %} class="active"{% endif %}><a href="{{ site.url }}/{{ item }}">{{ item|title }}</a></li>