insert_railsrc_into_argv!

# File railties/lib/rails/generators/rails/app/app_generator.rb, line 680
        def insert_railsrc_into_argv!(argv, railsrc)
          return argv unless File.exist?(railsrc)
          extra_args = read_rc_file railsrc
          argv.take(1) + extra_args + argv.drop(1)
        end