Psych YAML vulnerability on Heroku

check_for_yaml_vulnerability

# Built from https://gist.github.com/markpundsack/4506402
`heroku list`.split("\n").each do |app|
  app = app.strip

  # Some "heroku apps" lines have === formatting for grouping. They're not apps.
  next if app[0..2] == "==="

  # Some are appended by owner emails
  app = app.split(" ")[0].to_s.strip

  # Blank lines can be ommitted.
  next if app == ""

  yaml_version = `heroku run \"ruby -rpsych -e \\"p Psych.libyaml_version.join('.')\\"\" -a #{app}`

  if yaml_version.include?('LoadError')
    puts "#{app} is fine..."
  else
    puts "Please fix YAML for #{app}!"
  end
end