Bundler gem compatibility issues when deploying to heroku.

Question

I receive the following error message is when deploying to heroku:

Bundler could not find compatible version 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 (4.0.1.rc1)

Failed to install gems via Bundler

Gemfile

source 'https://rubygems.org'
ruby '1.9.3'

gem 'rails', '4.0.0'
gem 'bcrypt-ruby', '3.0.1'
gem 'faker', '1.1.2'
gem 'will_paginate', '3.0.4'
gem 'will_paginate-bootstrap'


group :development, :test do
  gem 'sqlite3', '1.3.7'
  gem 'rspec-rails', '2.13.1'
end

group :test do
  gem 'selenium-webdriver', '2.0.0'
  gem 'capybara', '2.1.0'
  gem 'factory_girl_rails', '4.2.1'
end

gem 'sass-rails', '4.0.0'
gem 'uglifier', '2.1.1'
gem 'coffee-rails', '4.0.0'
gem 'jquery-rails', '3.0.4'
gem 'turbolinks', '1.1.1'
gem 'jbuilder', '1.0.2'

group :doc do
  gem 'sdoc', '0.3.20', require: false
end

group :production do
  gem 'pg', '0.15.1'
  gem 'rails_12factor', '0.0.2'
end

I've tried many different things like running bundle update, changing gem versions etc. but so far nothing seems to work. I have been deploying to heroku for a while now without changing any of the gems, so how can this suddenly happen? Is this caused by the release of rails 4.0.1.rc1?