Upgrade to latest highlight.js

_includes/head.html

@@ -17,9 +17,8 @@
   <link rel="stylesheet" type="text/css" href="https://fonts.googleapis.com/css?family=PT+Sans:400,400italic,700|Abril+Fatface|Roboto+Mono">
   <meta name="description" content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
 
-  <!-- Include highlight.js 7 (8.8.0 did not work for me) -->
-  <link rel="stylesheet" href="https://yandex.st/highlightjs/7.5/styles/default.min.css">
-  <script src="https://yandex.st/highlightjs/7.5/highlight.min.js"></script>
+  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.6.0/styles/github.min.css">
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.6.0/highlight.min.js"></script>
 
 
   <!-- Include jquery.js -->