Bootstrap responsive nav hamburger menu not dropping items

Question

I am trying to make a responsive collapsible Bootstrap hamburger menu. The Hamburger menu shows up, but when I click it nothing collapses.

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

<nav class="navbar navbar-expand-md navbar-light">
  <div class="container-fluid">
    <a class="navbar-brand d-lg-none d-md-none d-sm-none" href="#">Navbar</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
                                                <span class="navbar-toggler-icon"></span>
                                              </button>

    <div class="collapse navbar-collapse" id="navbarSupportedContent">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item">
          <a class="nav-link navCol" href="index.html">Home</a>
        </li>
        <li class="nav-item">
          <a class="nav-link navCol" href="aboutme.html">About Me</a>
        </li>
        <li class="nav-item">
          <a class="nav-link navCol" href="#">Services</a>
        </li>
        <li class="nav-item">
          <a class="nav-link navCol" href="#">About Me</a>
        </li>
      </ul>
    </div>
  </div>
</nav>