<div class="row">
    <div class="col-md-12">
       <h1>Algunos de nuestros clientes</h1>
      <div id="owl-demo">
          <?php
              $args = array( 'post_type' => 'nuestrosclientes');
              $query = new WP_Query($args);
              $n=0;
              while($query -> have_posts()) : $query ->the_post();
              $n++;
          ?>
      <div class="<?php if($n==1) echo 'owl-item'; ?>" class="img-resposive" alt="Owl Image">
        <?php if (has_post_thumbnail() ) { the_post_thumbnail('nuestrosclientes'); } ?>
      </div>

      <div class="owl-controls clickable">
         <div class="owl-buttons">
            <div class="owl-prev"></div>
            <div class="owl-next"></div>
         </div>
      </div>
      <?php endwhile; ?>
  </div>