我有一个使用 Heroku 部署的 Rails 4.2 应用程序，并且尝试向其中添加 Google Analytics。但是，Google Analytics 没有获取任何会话。
有什么建议为什么以及如何解决这个问题吗？
CODE
/app/layouts/_footer.html.erb：
<% if Rails.env.production? %>
<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-XXXXXXXX-X', 'herokuapp.com');
ga('send', 'pageview');
</script>
<% end %>
/app/layouts/application.html.erb：
<!DOCTYPE html>
<html>
<head>
<title>Title</title>
<%= Gon::Base.render_data({}) %>
<%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track' => true %>
<%= javascript_include_tag 'application', 'data-turbolinks-track' => true %>
<%= csrf_meta_tags %>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<div class="container">
<%= yield %>
</div>
<%= render 'layouts/footer' %>
</body>
</html>
/app/assets/javascripts/analytics.js.coffee：
$(document).on 'page:change', ->
if window._gaq?
_gaq.push ['_trackPageview']
else if window.pageTracker?
pageTracker._trackPageview()
/app/assets/javascripts/application.js：
//= require jquery
//= require analytics
//= require bootstrap
//= require jquery_ujs
//= require jquery.ui.all
//= require Chart
//= require jquery.turbolinks
//= require lodash
//= require_tree .
Gemfile:
source 'https://rubygems.org'
gem 'rails', '4.2.2'
gem 'bootstrap-sass', '3.2.0.0'
gem 'sass-rails', '5.0.2'
gem 'uglifier', '2.5.3'
gem 'coffee-rails', '4.1.0'
gem 'jquery-rails', '4.0.3'
gem 'jquery-ui-rails', '~> 4.2.1'
gem 'turbolinks', '2.3.0'
gem 'jquery-turbolinks'
gem 'jbuilder', '2.2.3'
gem 'sdoc', '0.4.0', group: :doc
gem 'chart-js-rails'
gem 'gon'
gem 'lodash-rails'
group :development, :test do
gem 'sqlite3', '1.3.9'
gem 'byebug', '3.4.0'
gem 'web-console', '2.0.0.beta3'
gem 'spring', '1.1.3'
end
group :production do
gem 'pg', '0.17.1'
gem 'rails_12factor', '0.0.2'
end
