docs: switch to the Universal Analytics code.

docs/_includes/header.html

@@ -17,13 +17,10 @@
 <link rel="apple-touch-icon-precomposed" sizes="114x114" href="/assets/img/apple-touch-icon-114x114.png">
 
 <script>
-  var _gaq = _gaq || [];
-  _gaq.push(['_setAccount', 'UA-36050008-1']);
-  _gaq.push(['_trackPageview']);
-
-  (function() {
-    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
-    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
-    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
-  })();
+  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+  })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
+  ga('create', 'UA-36050008-1', 'goratchet.com');
+  ga('send', 'pageview');
 </script>