added $PORT to Procfile
added Ruby version to Gemfile
only show 'Create a function' button to logged-in users
updated home_controller to redirect back to http after login
back to eagerly serving all JS

It's just a lot easier to do this and have scripts selectively
disable themselves. Admittedly, it's also uglier. I will have to
think about (i.e., *read* about) a better approach here.
updated seeds.rb w/ tests for chunk function
reduced minimum CodeMirror height
set a timeout on test-running web worker