add Google Analytics tag
diff --git a/includes/header.php b/includes/header.php
index 754ab32..f4c9793 100644
--- a/includes/header.php
+++ b/includes/header.php
@@ -29,7 +29,17 @@
 	<!-- Showdown Markdown converter --> 
 	<script src="//cdnjs.cloudflare.com/ajax/libs/showdown/0.3.1/showdown.min.js"></script>
 	    
-	<!-- TODO Google Analytics? -->
+	<!-- Google Analytics? -->
+	<script>
+	  (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-5683118-6', 'auto');
+	  ga('send', 'pageview');
+
+	</script>
 </head>
 <body>
 	<!-- Navbar -->