<a href="#top" target="_self" class="btn btn-info btn-xs">Return to Top</a>

style = "margin: 0 auto"
style = "text-align: center"
class="btn btn-info btn-xs center-block"

<div class="col-md-10 col-md-offset-1">
    <ui-view></ui-view>
</div>

<div class="text-center">
  <a href="#top" target="_self" class="btn btn-info btn-xs">Return to Top</a>
</div>