added exempt xframe header for renkan edit, create and display views.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<h4>Mock GED client</h4>
<p>Client Credentials OAuth token owner is: {{ oauth_username }}</p>
<p>Logged user is: {{ current_username }}</p>
<p>Create a <a href="{{ config['CREATE_RENKAN_URL'] }}">new Renkan</a> and edit (authorization flow)</p>
<p>Create a <a href="{{ url_for('renkan_request') }}">new Renkan</a> from server (clients credentials)</p>
</body>
</html>