Patch Berkshelf to keep a cookbook's .git folder

berkshelf.patch

--- a/vendor/gems/ruby/1.9.1/gems/berkshelf-1.0.4/lib/berkshelf/berksfile.rb
+++ b/vendor/gems/ruby/1.9.1/gems/berkshelf-1.0.4/lib/berkshelf/berksfile.rb
@@ -38,10 +38,6 @@
           # Dir.glob does not support backslash as a File separator
           src = cb.path.to_s.gsub('\\', '/')
           FileUtils.cp_r(Dir.glob(File.join(src, "*")), dest)
+
+          # Copy .git dir if present
+          git_dir = File.join(src, ".git")
+          FileUtils.cp_r(git_dir, dest) if File.exists?(git_dir)
         end
 
         FileUtils.remove_dir(path, force: true)