Supporting SSL requires a slight tweak to the JavaScript embed code.  Simply replace spn.ee with d2c830s9k3e6a5.cloudfront.net in the code.

The updated code should look like (be sure to set your site id):

<script>var _spinnakr_site_id="[YOUR SITE ID HERE]";(function(d,t,a){var g=d.createElement(t),s=d.getElementsByTagName(t)[0];g[a]=a;g.src='//d2c830s9k3e6a5.cloudfront.net/js/so.js';s.parentNode.insertBefore(g,s)}(document,'script','async'))</script>