support for chef solo environments, upcoming in chef 11.6

Add support for new chef solo provisioner configuration options, ``environment`` and ``environments_path``. This allows for  chef environments to be used in chef-solo provisioned VMs.

The necessary chef-solo support for environments is available in the upcoming 11.6 chef release.   If ``environment`` is specified for a VM using an earlier version of chef, provisioning will fail with a missing client pem error during the chef-client run.