[CHEF-4334] Can't parse release candidate version number

http://tickets.opscode.com/browse/CHEF-4334

Error when using a release candidate

```text
/usr/local/rbenv/versions/2.0.0-p195/lib/ruby/gems/2.0.0/gems/chef-11.6.0.rc.0/lib/chef/version_class.rb:65:in `parse'
:
deploy_revision[railsapp] (/tmp/vagrant-chef-1/chef-solo-1/cookbooks/application/providers/default.rb line 122) had an error:
Chef::Exceptions::InvalidCookbookVersion: application_ruby_rails[railsapp] (enquirli::test line 115) had an error:
Chef::Exceptions::InvalidCookbookVersion: '11.6.0.rc.0' does not match 'x.y.z' or 'x.y' (Chef::Exceptions::InvalidCookbookVersion)
```