title: Bootstrap 4 card-footer does not align to the bottom of the page
body: <p>I am using Bootsrap 4 cards' class 'card-footer', but the footer is not aligning to the bottom of the page.</p>
  
  <p>Here is the link <a href="https://jsfiddle.net/37g8yufn/8/" rel="noreferrer">to the js fiddle</a></p>
  
  <pre><code>&lt;div class="container"&gt;
     &lt;div class="card text-center"&gt;
       &lt;div class="card-header"&gt;Featured&lt;/div&gt;
       &lt;div class="card-body"&gt;
         &lt;h5 class="card-title"&gt;Special title treatment&lt;/h5&gt;
         &lt;p class="card-text"&gt;This text should be equi-distance from header 
         and footer. &lt;/p&gt;
         &lt;p class="card-text"&gt;
         Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Nullam 
         sapien sem, ornare ac, nonummy non, lobortis a enim. Nam sed 
         tellus id magna elementum tincidunt. Pellentesque habitant morbi 
         tristique senectus et netus et malesuada fames ac turpis egestas. 
         Aliquam ornare wisi eu metus. In enim a arcu imperdiet malesuada. 
         Nam quis nulla. Vivamus luctus egestas leo. 
         &lt;/p&gt;
     &lt;/div&gt;
     &lt;div class="card-footer text-muted"&gt;
      This footer should be at the bottom
    &lt;/div&gt;
   &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>