<div class="navbar-area">
  <?php
    $categories = get_categories( array(
      'orderby' => 'name',
      'order'   => 'ASC'
    ) );

    foreach( $categories as $category ) {
      if ($category->slug == "blog") {
        echo '<a class="btn btn-navbar" href="' . get_category_link($category->term_id) . '">' . $category->name . '</a>';
        }
    }?>
  <!-- <a href="/blog.html" class="btn btn-navbar">Blog</a> -->
  <!-- <a href="/crea.html" class="btn btn-navbar">Romans</a> -->
  <!-- <a href="/apropos.html" class="btn btn-navbar">A propos</a> -->
  <a href="<?php bloginfo('rss2_url'); ?>" class="btn btn-navbar"><i class="fa fa-rss"></i></a>
</div>