Stop uploading empty directories

Author: Matt Whiteley

lib/kitchen/provisioner/chef_base.rb

@@ -292,6 +292,8 @@ def prepare_cookbooks
       def filter_only_cookbook_files
         info("Removing non-cookbook files before transfer")
         FileUtils.rm(all_files_in_cookbooks - only_cookbook_files)
+        Dir.glob(File.join(tmpbooks_dir, "**/"), File::FNM_PATHNAME).
+          reverse_each { |fn| FileUtils.rmdir(fn) if Dir.entries(fn).size == 2 }
       end
 
       # Generates a list of all files in the cookbooks directory in the