Bootstrap Table Dashes

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.11.0/bootstrap-table.min.js"></script>
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.11.0/bootstrap-table.min.css">
<table id="table" class="table">
  <thead>
    <tr>
      <th data-field="BookTitle">Title</th>
    </tr>
  </thead>             
</table>

JavaScript

var testData = [
	{"BookTitle": "abc"},
  {"BookTitle": "def"},
  {"BookTitle": null}
];

$('#table').bootstrapTable({
            data: testData
        });