Numergy/ndenv-cookbook — pull request #2 by PierreRambaud (2014-09-25 11:07:57+00:00)
Title: Ndenv_npm does not install package

Seems packages aren't installed when there's no version specified,
so after looking the source of the `chef/provider/package.rb`
file (https://github.com/opscode/chef/blob/master/lib/chef/provider/package.rb#L59),
if there is no version the value of attribute :version must be
nil instead of empty string.