add version to GA event tracking.

frontend/app/lib/analytics.js

 /*global ga*/
 
+import MetabaseSettings from "metabase/lib/settings";
+
+
 // Simple module for in-app analytics.  Currently sends data to GA but could be extended to anything else.
 var MetabaseAnalytics = {
     // track a pageview (a.k.a. route change)
@@ -15,8 +18,11 @@ var MetabaseAnalytics = {
 
     // track an event
     trackEvent: function(category, action, label, value) {
+        const { tag } = MetabaseSettings.get('version');
+
         // category & action are required, rest are optional
         if (category && action) {
+            ga('set', 'dimension1', tag);
             ga('send', 'event', category, action, label, value);
         }
     }