How to remove the border-bottom from bootstrap navbar

There is a box shadow added by the bootstrap theme. The following rules will remove it as well as on the .navbar-collapse class when the nav is under 768px.

Note: you have a stray tag after the fa fa-user button and are (possibly) using normalize.css twice since Bootstrap3 uses a version of it all ready. See normalize.less.

.navbar.navbar-default {
    background-color: #99ccff;
    border: 0;
    -webkit-box-shadow: none;
    box-shadow: none;
}

.navbar.navbar-default .navbar-collapse {
    border: 0;
    -webkit-box-shadow: none;
    box-shadow: none;
}

Before with box-shadow:

enter image description here

After removing the box-shadow:

enter image description here

Working Example:

/*FOR DEMO ONLY*/

html,
body {
  background: aliceblue;
}
/*FOR DEMO ONLY*/

.nav-container {
  border-width: 0;
  box-shadow: none;
  background-color: aliceblue;
}
.navbar.navbar-default {
  background-color: #99ccff;
  border: 0;
  -webkit-box-shadow: none;
  box-shadow: none;
}
.navbar.navbar-default .navbar-collapse {
  border: 0;
  -webkit-box-shadow: none;
  box-shadow: none;
}
<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.6/css/bootstrap-theme.css">
<link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css">
<header>
  <nav class="navbar navbar-default navbar-fixed-top" role="navigation">
    <div class="container-fluid nav-container">
      <div class="navbar-header">
        <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#Writers-Tryst">
          <span class="sr-only">Toggle navigation</span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
        </button>
        <div style="display: inline-block">
          <a class="navbar-brand" href="#">
            <img id="logo" src="https://writers-tryst.com//img/writers-tryst-logo-min.png" alt="logo" />
          </a>
          <br/>
          <br/>
          <div id="shares" class="row">
            <a href="http://twitter.com/share?url=writers.tryst.ron-tornambe.com&text=<TEXT>&via=<VIA>" target="_blank" title="twitter" class="share-btn twitter">
              <i class="fa fa-twitter"></i>
            </a>
            <a href="http://www.facebook.com/sharer/sharer.php?u=http://writers.tryst.com" target="_blank" title="facebook" class="share-btn facebook">
              <i class="fa fa-facebook"></i>
            </a>
            <a href="http://www.linkedin.com/shareArticle?url=http://writers.tryst.com&title=<TITLE>&summary=<SUMMARY>&source=<SOURCE_URL>" target="_blank" title="linked-in" class="share-btn linkedin">
              <i class="fa fa-linkedin"></i>
            </a>
            <a href="https://plus.google.com/share?url=writers.tryst.ron-tornambe.com" target="_blank" title="google+" class="share-btn google-plus">
              <i class="fa fa-google-plus"></i>
            </a>
          </div>
        </div>
      </div>
      <div class="collapse navbar-collapse" id="Writers-Tryst">
        <ul class="nav navbar-nav">
          <li class="active"><a id="homepage" href="#/"><i class="acctive glyphicon glyphicon-home fa fa-home"></i> Home</a>
          </li>
          <li><a href="#writers" id="writers-link" class="fa fa-book"> Writers</a>
          </li>
          <li><a href="#enablers" id="enablers-link" class="fa fa-thumbs-o-up"> Enablers</a>
          </li>
          <li><a href="#about" class="fa fa-info-circle"> About</a>
          </li>
          <li><a href="#privacy" class="fa fa-user-secret"> Privacy/Rules</a>
          </li>
          <li><a href="#contact" class="fa fa-envelope-o"> Contact</a>
          </li>
        </ul>
        <ul class="nav navbar-nav navbar-right">
          <li><a id="login" href="#log-in"><i class="fa fa-sign-in"></i> Log-In</a>
          </li>
          <li><a id="accounts-link" href="#accounts"><i class="fa fa-user hidden"></i> Create Account</a>
          </li>
          <li class="dropdown" data-toggle="popover" data-trigger="hover" data-placement="bottom">
            <button class="btn btn-custom-primary dropdown-toggle fa fa-user" style="margin-top: 8px; color: white;" data-html="true" type="button" id="user-dropdown-link" data-toggle="dropdown"><span class="caret"></span>
            </button>
            <ul class="dropdown-menu" role="menu" data-aria-labelledby="create-account-link">
              <li><a id="update-profile" href="#update-profile" class="fa fa-database"> Update profile</a>
              </li>
              <li><a id="manage-uploads" href="#manage-uploads" class="fa fa-book"> Manage uploads</a>
              </li>
              <li><a id="review-submissions" href="#review-submissions" class="fa fa-book"> Review Submissions</a>
              </li>
              <li><a id="update-submissions" href="#update-submissions" class="fa fa-book"> Update Reviews</a>
              </li>
            </ul>
          </li>
          <li>
            <a id="reset-pwd-link" href="#reset-pwd"></a>
          </li>
        </ul>
      </div>
    </div>
  </nav>
</header>
<div>
  <div id="message" class="alert m-t-10 m-b-10"></div>
  <div id="main" class="content container">
    <div data-ng-view></div>
  </div>
  <footer class="panel panel-default panel-transparent">
    <div id="footer" class="text-right small">&#169; 2016 Ronald Tornambe, Inc.</div>
  </footer>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>


simply apply box-shadow: none; in navbar