I was trying to add the github (`class="fas fa-github"`) icon on a bootstrap dark button, but the button icon and text doesn't appear (the console shows nothing)

Code:

```
<div class="jumbotron">
    <h1 class="display-4">Henrique Borges</h1>
    <p class="lead">Programador experiente e Web Designer.</p>
    <hr class="my-4">
    <p>It uses utility classes for typography and spacing to space content out within the larger container.</p>
    <p class="lead">
    <a class="fas fa-github btn btn-dark btn-lg" href="#" role="button">Github</a>
    </p>
</div>

```

I´ve already included both the BS and FA libraries:

```
<link rel="stylesheet" href="css/bootstrap.min.css">
<script src="js/jquery-3.2.1.min.js"></script>
<script src="js/fontawesome-all.min.js"></script>

```