<header><nav class="navbar navbar-default navbar-fixed-top" role="navigation">
  <div class="container">

    <m-player-controls></m-player-controls>

    <ul m-navigation class="nav navbar-nav hidden-xs"></ul>

    <div class="burger btn-group visible-xs-block" dropdown>
      <button type="button" class="btn btn-primary dropdown-toggle">
        <i class="fa fa-2x fa-navicon"></i>
      </button>
      <ul m-navigation class="dropdown-menu" role="menu"></ul>
    </div>

  </div>
</nav></header>

<header><nav class="navbar navbar-default navbar-fixed-top" role="navigation">
  <div class="container">

    <m-player-controls></m-player-controls>

    <ul m-navigation class="nav navbar-nav hidden-xs"></ul>

    <div class="burger btn-group visible-xs-block" uib-dropdown>
      <button type="button" class="btn btn-primary dropdown-toggle"
        uib-dropdown-toggle
      >
        <i class="fa fa-2x fa-navicon"></i>
      </button>
      <ul m-navigation class="dropdown-menu" role="menu"></ul>
    </div>

  </div>
</nav></header>

Fix burger menu for small screens
Fix burger menu for small screens

It required the same changes as other dropdowns, since the recent
ui-bootstrap upgrade.
