added "name" setting to metadata.

"name" setting is needed to prevent the following error on Vagrant 1.5.3 and vagrant-berkshelf 2.0.0.rc3:
> /home/jharai/.vagrant.d/gems/gems/ridley-3.0.0/lib/ridley/chef/cookbook.rb:44:in `from_path': The metadata at '/tmp/d20140416-24840-14l59qn' does not contain a  'name' attribute. While Chef does not strictly enforce this requirement, Ridley cannot continue without a valid metadata 'name' entry. (Ridley::Errors::MissingNameAttribute)