added google analytics

src/components/GAnalytics.jsx

@@ -0,0 +1,29 @@
+import React from 'react'
+
+function script(account) {
+    return `
+        if (window.location.host.indexOf('localhost') === -1) {
+            (function (window, document, script, src, ga, element, m) {
+                window['GoogleAnalyticsObject'] = ga;
+                if (!window[ga]) {
+                    window[ga] = function () {
+                        (window[ga].q = window[ga].q || []).push(arguments)
+                    }
+                }
+                window[ga].l = 1 * new Date();
+                element = document.createElement(script);
+                m = document.getElementsByTagName(script)[0];
+                element.async = 1;
+                element.src = src;
+                m.parentNode.insertBefore(element, m)
+            })(window, document, 'script', '//www.google-analytics.com/analytics.js', 'ga');
+
+            ga('create', '${account}', 'auto');
+            ga('send', 'pageview');
+        }
+    `
+}
+
+export const GAnalytics = (props) => (
+    <script dangerouslySetInnerHTML={{ __html: script(props.account) }} />
+)