Support vagrant port forwarding configuration

[almog]

Hi, I've recently migrated a Vagrantfile with its vm definitions to using gusteau's vagrant provisioning.

However, Vagrant's port_forwarding options are not supported as part of gusteau configuration.

That leaves the following definition in the Vagrantfile:

Vagrant.configure("2") do |config|
  config.vm.network "forwarded_port", guest: 80, host: 8080
end

Are there any plans to somehow express this definition as part of .gusteau.yml, in somewhat similar fashion to this:

vagrant:
  network:
    forwarded_port:
      guest: 80
      host: 8080

Or maybe you think some definitions which are not expressed as key/value with Vagrant DSL should not be converted to yaml?

[Deleted user]

My idea of the Vagrant plugin was for it to help with configuration but not necessarily embrace all of it.
I wouldn't mind such a pull request anyway :)