I am trying to upgrade to Rails 4.0.0, and I changed the gem versions of `sass-rails` and `coffee-rails`. I need to resolve this gem conflict between `rails` and `coffee-rails` before I can upgrade to Rails 4.

When I ran `bundle update` this is the output I got:

```
$ bundle update
Updating git://github.com/pilu/web-app-theme.git
Fetching source index from https://rubygems.org/
Resolving dependencies..............
Bundler could not find compatible versions for gem "railties":
  In Gemfile:
    rails (= 4.0.0) ruby depends on
      railties (= 4.0.0) ruby

    coffee-rails (= 4.0.0) ruby depends on
      railties (4.0.0.rc2)

```

My `Gemfile`:

```
source 'https://rubygems.org'

gem 'rails', '4.0.0'

gem 'cancan'
gem 'client_side_validations'
gem 'devise', '~> 1.5.3'
gem 'dynamic_form'
gem 'execjs'
gem 'haml'
gem 'httparty'
gem 'jquery-rails'
gem 'mysql2'
gem 'paperclip', '~> 2.4'
gem 'prawn'
gem 'rails3-jquery-autocomplete'
gem 'rake', '0.9.2'
gem 'remotipart', '~> 1.0'
gem 'simple_datatables'
gem 'therubyracer'
gem 'validates_timeliness', '~> 3.0.2'
gem 'will_paginate', '~> 3.0'

gem 'turbolinks'
gem 'jquery-turbolinks'

gem 'noty-rails'

gem 'font-awesome-rails'

gem 'socket.io-rails'

gem 'attr_encrypted'

gem 'bullet', :group => 'development'

#temp for demo.managetherapy.com
#gem 'faker'

group :test do
  gem 'capybara'
  gem 'cucumber-rails', :require => false
  gem 'database_cleaner'
  gem 'factory_girl_rails'
#  gem 'faker'
  gem 'guard-rspec'
  gem 'selenium-webdriver', '2.7.0'
  gem 'webrat'
end

group :development, :test do
  gem 'faker'
  gem 'haml-rails'
  gem 'hpricot'
  gem 'rspec-rails'
  gem 'ruby_parser'
  #gem 'web-app-theme', '~> 0.8.0'
  gem 'web-app-theme', :git =>'git://github.com/pilu/web-app-theme.git'
end

gem 'sass-rails', '4.0.0'
gem 'compass-rails', '1.0.3'
gem 'coffee-rails', '4.0.0'
gem 'uglifier', '>= 2.1.1'
gem 'bootstrap-sass-rails'

# Use unicorn as the web server
#gem 'unicorn'

# Deploy with Capistrano
gem 'capistrano'
gem 'rvm-capistrano'

gem 'passenger'

```