Teeny-tiny sinatra app on heroku

app.rb

require 'rubygems'
require 'sinatra'

configure do
  set :public_folder, Proc.new { File.join(root, "static") }
  enable :sessions
end

get '/' do
  erb :index
end

Gemfile

source :rubygems

gem "thin"
gem "sinatra"

group :development do
  gem "heroku"
  gem "foreman"
end

Procfile

web: bundle exec ruby app.rb -p $PORT