this rack app will return whatever http status code you want, too.

config.ru

# https://gist.github.com/wwalexander/febbc1ba76c8eafa9f94f5cb2573b34d
# https://news.ycombinator.com/item?id=17235270
#
# Make sure this is named config.ru 
# install the gem with 
# $ gem install rack
#
# Usage: rackup 

require 'rack'

run ->(env) { [(env['REQUEST_PATH'][-3, 3].to_i.nonzero? ? env['REQUEST_PATH'][-3, 3].to_i : 200), {"Content-Type" => "text/html"}, [' ']] }