<div class="btn-group dropup">
    <button class="btn btn-primary">Dropup</button>
    <button class="btn btn-primary dropdown-toggle" data-toggle="dropdown"><i class="fa fa-caret-up "></i></button>
    <ul class="dropdown-menu">
      <li><a href="#">Action</a></li>
      <li><a href="#">Another action</a></li>
      <li><a href="#">Something else here</a></li>
      <li class="divider"></li>
      <li><a href="#">Separated link</a></li>
    </ul>
  </div>