Ваш код хорошо работает для меня. Не могли бы вы показать, как вы ссылались на файл jQuery?
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
</head>
<body>
<nav class="navbar navbar-expand-sm navbar-dark bg-dark">
<a class="navbar-brand" href="#">
Spritual yatra
</a>
<button type="button" class="navbar-toggler" data-toggle="collapse" data-target="#myMenu">
<span class="navbar-toggler-icon"></span>
</button>
<div class="navbar-collapse collapse " id="myMenu">
<ul class="navbar-nav ml-auto">
<li class="nav-item"><a href="#" class="nav-link active">Home</a></li>
<li class="nav-item"><a href="#" class="nav-link">About us</a></li>
<li class="nav-item"><a href="#" class="nav-link">Contact</a></li>
</ul>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</body>
</html>
Вы попробовали
config.before(:type => :controller) do
request.env["HTTP_REFERER"] = "/"
end