Lazyatom Vanilla.rb

Get the console to load the app as configured in config.ru

I don't love extracting configuration into static files, and this trick allows us to use the config.ru file as-is, but return the initialized app. It won't work for more sophisticated setups (like, say, multiple Vanilla::App instances mounted at different points within the same config.ru), but that's good enough for now.
https://github.com/lazyatom/vanilla-rb/commit/6a0f952d349dc04a33aba...