Added missing collapse class.

The collapsed navbar does not increase height to accomodate dropdowns without it.

templates/header-top-navbar.php

@@ -9,7 +9,7 @@
       <a class="brand" href="<?php echo home_url(); ?>/">
         <?php bloginfo('name'); ?>
       </a>
-      <nav class="nav-main nav-collapse" role="navigation">
+      <nav class="nav-main nav-collapse collapse" role="navigation">
         <?php
           if (has_nav_menu('primary_navigation')) :
             wp_nav_menu(array('theme_location' => 'primary_navigation', 'menu_class' => 'nav'));