navbar-brand and toggler-icon are ignoring margins and centering on xs only

<!--Navbar -->  
    <nav class="navbar navbar-toggleable-sm navbar-inverse bg-primary">
      <div class="container"> <!--Nav Container -->
        <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
          <span class="navbar-toggler-icon"></span>
        </button>
        <div class="collapse navbar-collapse" id="navbarNav">
          <ul class="navbar-nav mr-auto">
            <li class="nav-item">
              <a class="nav-link" href="#">Home</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#about">About</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#speakers">Speakers</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#schedule">Schedule</a>
            </li>
          </ul>
        </div>
          <a class="navbar-brand" href="http://www.teamtreehouse.com">Presented by Treehouse</a>   
     </div> <!--End Nav Container-->
  </nav> <!--End Navbar -->