Use DIR instead of FileUtils in bin/setup script

bin/setup

@@ -1,5 +1,4 @@
 #!/usr/bin/env ruby
-require 'fileutils'
 
 # path to your application root.
 APP_ROOT = File.expand_path('..', __dir__)
@@ -8,7 +7,7 @@ def system!(*args)
   system(*args, exception: true)
 end
 
-FileUtils.chdir APP_ROOT do
+Dir.chdir APP_ROOT do
   # This script is a way to set up or update your development environment automatically.
   # This script is idempotent, so that you can run it at any time and get an expectable outcome.
   # Add necessary setup steps to this file.