Cleanup default analytics function

index.js

@@ -272,7 +272,9 @@ Pjax.prototype = {
     // Fire Events
     trigger(document,"pjax:complete pjax:success", state.options)
 
-    state.options.analytics()
+    if (typeof state.options.analytics === "function") {
+      state.options.analytics()
+    }
 
     if (state.options.history) {
       // First parse url and check for hash to override scroll

lib/proto/parse-options.js

@@ -10,9 +10,6 @@ module.exports = function(options) {
   this.options.switchesOptions = this.options.switchesOptions || {}
   this.options.history = this.options.history || true
   this.options.analytics = this.options.analytics || function() {
-    // options.backward or options.foward can be true or undefined
-    // by default, we do track back/foward hit
-    // https://productforums.google.com/forum/#!topic/analytics/WVwMDjLhXYk
     if (window._gaq) {
       _gaq.push(["_trackPageview"])
     }
@@ -36,7 +33,4 @@ module.exports = function(options) {
   if (!this.options.switches.body) {
     this.options.switches.body = defaultSwitches.switchElementsAlt
   }
-  if (typeof options.analytics !== "function") {
-    options.analytics = function() {}
-  }
 }