Added rspec, factory_girl, capybara and webrat

Added the following gems:

  * rspec
  * rspec-rails
  * factory_girl
  * ffaker
  * webrat
  * capybara
  * launchy
  * database_cleaner

Now the new Rails app will:

  * Create rspec-rails enabled tests
  * Create factory_girl model stubs
  * Create integration tests with Capybara

Also, the default rails generator is set to not produce test_unit
files.