create_root

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 213
      def create_root
        self.destination_root = File.expand_path(app_path, destination_root)
        valid_app_const?

        empty_directory '.'
        set_default_accessors!
        FileUtils.cd(destination_root) unless options[:pretend]
      end