add selenium driver to prod env

Gemfile

@@ -41,6 +41,7 @@ gem 'httparty'
 gem 'discourse_api'
 gem 'abstract_type'
 
+gem 'selenium-webdriver'
 
 group :development do
   # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
@@ -54,7 +55,6 @@ end
 group :test do
   # Adds support for Capybara system testing and selenium driver
   gem 'capybara', '>= 2.15'
-  gem 'selenium-webdriver'
   # Easy installation and use of chromedriver to run system tests with Chrome
   gem 'chromedriver-helper'
 end