add_options!

# File railties/lib/rails_generator/generators/applications/app/app_generator.rb, line 91
    def add_options!(opt)
      opt.separator ''
      opt.separator 'Options:'
      opt.on("--ruby [#{DEFAULT_SHEBANG}]",
             "Path to the Ruby binary of your choice.") { |options[:shebang]| }
      opt.on("--without-gems",
             "Don't use the Rails gems for your app.",
             "WARNING: see note below.") { |options[:gem]| }
    end