Use https:// in the Google Analytics snippet

Nowadays HTTPS is fast and increasingly necessary, so using
protocol-relative URLs is becoming an anti-pattern, especially for CDNs.

From https://developers.google.com/speed/libraries/devguide?csw=1#libraries:

 " We recommend that you load libraries from the CDN via HTTPS, even
   if your own website only uses HTTP. Nowadays, performance is fast
   and caching works just the same "

See also: https://github.com/konklone/cdns-to-https#conclusion-cdns-should-redirect-to-https

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### HEAD
 
+* Use `https://` in the Google Universal Analytics snippet.
 * Include the `LICENSE.txt` file in the `dist/` directory
   ([#1655](https://github.com/h5bp/html5-boilerplate/issues/1655)).
 * Remove the `visibility: hidden` declaration from `.hidden`

dist/index.html

@@ -32,7 +32,7 @@
             (function(b,o,i,l,e,r){b.GoogleAnalyticsObject=l;b[l]||(b[l]=
             function(){(b[l].q=b[l].q||[]).push(arguments)});b[l].l=+new Date;
             e=o.createElement(i);r=o.getElementsByTagName(i)[0];
-            e.src='//www.google-analytics.com/analytics.js';
+            e.src='https://www.google-analytics.com/analytics.js';
             r.parentNode.insertBefore(e,r)}(window,document,'script','ga'));
             ga('create','UA-XXXXX-X','auto');ga('send','pageview');
         </script>

src/index.html

@@ -32,7 +32,7 @@
             (function(b,o,i,l,e,r){b.GoogleAnalyticsObject=l;b[l]||(b[l]=
             function(){(b[l].q=b[l].q||[]).push(arguments)});b[l].l=+new Date;
             e=o.createElement(i);r=o.getElementsByTagName(i)[0];
-            e.src='//www.google-analytics.com/analytics.js';
+            e.src='https://www.google-analytics.com/analytics.js';
             r.parentNode.insertBefore(e,r)}(window,document,'script','ga'));
             ga('create','UA-XXXXX-X','auto');ga('send','pageview');
         </script>