Rake de deploy para o Heroku

.rvmrc

export AMAZON_S3_BUCKET=mybucket-development
export AMAZON_ACCESS_KEY_ID=xxx
export AMAZON_SECRET_ACCESS_KEY=xxx
rvm 1.9.2@nome-da-app --create

deploy.rake

namespace :heroku do
  APP = 'nome-da-app'

  def run(*cmd)
    system(*cmd)
    raise "Command #{cmd.inspect} failed!" unless $?.success?
  end

  desc "Deploy app to Heroku"
  task :deploy do
    puts "-----> Pushing..."
    run "git push git@heroku.com:#{APP}.git HEAD:master -f"

    puts "-----> Migrating..."
    run "heroku run rake db:migrate --app #{APP}"

    puts "-----> Restarting..."
    run "heroku restart --app #{APP}"
  end
end