Adding asterisk to required fields in Bootstrap 3

My HTML has a class called .required that is assigned to required fields. Here is the HTML: <form action=”/accounts/register/” method=”post” role=”form” class=”form-horizontal”> <input type=”hidden” name=”csrfmiddlewaretoken” value=”brGfMU16YyyG2QEcpLqhb3Zh8AvkYkJt” /> <div class=”form-group required”> <label class=”col-md-2 control-label”>Username</label> <div class=”col-md-4″> <input class=”form-control” id=”id_username” maxlength=”30″ name=”username” placeholder=”Username” required=”required” title=”” type=”text” /> </div> </div> <div class=”form-group required”><label class=”col-md-2 control-label”>E-mail</label><div class=”col-md-4″><input class=”form-control” id=”id_email” … Read more