Replace mechanize gem by selenium webdriver

Some years ago, the Mechanize gem was used by quite a lot of Ruby developers to exact web contents for testing or other uses.

However, the down side of Mechanize is that it cannot get delayed contents from AJAX. Selenium webdriver came to solve the problem.

The Selenium driver will launch a browser to simulate real user interaction with the target web site.  So, the AJAX and other contents can be easily found using the selenium driver APIs.

http://seleniumhq.org/