Can anyone help me troubleshoot the code in my attempt to make an image responsive and center it? I've been struggling with this issue and can't figure out what I'm doing wrong. Here's an example of how it currently looks on my screen: https://i.sstatic.net/DYf8m.jpg
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<div class="row">
<div class="col-md-4">
<div class="thumbnail">
<a href="http://i1126.photobucket.com/albums/l611/ldocherty1/IMG_0730_zpsiz4dqc47.jpg" target="_blank">
<img src="http://i1126.photobucket.com/albums/l611/ldocherty1/IMG_0730_zpsiz4dqc47.jpg" alt="picture" class="img-responsive center-block" />
</a>
</div>
</div>
</div>
</div>
</body>
</html>