Hi I am unable to install Web-app-theme on Rails 4

[seshendramln]

Hi,
I am newbie to rails I wanted to install web app theme to my rails app. http://blog.bryanbibat.net/2011/09/24/starting-a-professional-rails-3-1-app-with-web-app-theme-devise-and-kaminari/

I have started following these tutorials and as well as Readme file from your repository.
When I try to add to the gem file I am getting the following error

Bundler could not find compatible versions for gem "rails":
In Gemfile:
web-app-theme (> 0.8.0) ruby depends on
rails (> 3.1.0.rc6) ruby

rails (4.0.2)

Can you please help me to solve it