Gemfile in active_admin_datetimepicker-0.6.2 vs Gemfile in active_admin_datetimepicker-0.6.3

@@ -1,20 +1,21 @@
 source 'https://rubygems.org'
 
 # Specify your gem's dependencies in active_admin_datetimepicker.gemspec
 gemspec
 group :test do
-  default_rails_version = '4.2.7'
-  default_activeadmin_version = '1.1.0'
-  gem 'sprockets-rails', '2.3.3'
-  gem 'rails', "#{ENV['RAILS'] || default_rails_version}"
+  default_rails_version = '5.2.1'
+  default_activeadmin_version = '1.3.1'
+
+  gem 'rails', "~> #{ENV['RAILS'] || default_rails_version}"
+  gem 'activeadmin', "~> #{ENV['AA'] || default_activeadmin_version}"
+
   gem 'rspec-rails'
-  gem 'activeadmin', "#{ENV['AA'] || default_activeadmin_version}"
   gem 'coveralls', require: false # Test coverage website. Go to https://coveralls.io
   gem 'sass-rails'
   gem 'sqlite3'
   gem 'launchy'
   gem 'database_cleaner'
   gem 'capybara'
   gem 'selenium-webdriver'
-  gem 'poltergeist'
+  gem 'chromedriver-helper'
 end