title: how could i remove a thin line between navigation bar and carousel
body: <p>screenshot: <a href="http://i.stack.imgur.com/vAvwn.png" rel="nofollow">thin white line between navbar and carousel</a></p>
  
  <p>any ideas how could i remove that thin white line? my navbar is into a container &amp; fixed top. My carousel is into another container-fluid.</p>