add builder 3.2.2 to Gemfile.sh and use that instead of vendored copy

Gemfile.sh

@@ -6,3 +6,4 @@ gem install rack    -v=1.4.5
 gem install erubis  -v=2.7.0
 gem install json    -v=1.8.0
 gem install i18n    -v=0.6.9
+gem install builder -v=3.2.2

activesupport/lib/active_support/vendor.rb

 # Prefer gems to the bundled libs.
 require 'rubygems'
 
-begin
-  gem 'builder', '~> 2.1.2'
-rescue Gem::LoadError
-  $:.unshift "#{File.dirname(__FILE__)}/vendor/builder-2.1.2"
-end
 require 'builder'
 
 begin