test: exercise the driver through Test Kitchen against a stubbed vRA

[tas50]

There was no kitchen.yml anywhere in this repo and nothing that ran the driver through Test Kitchen at all. The unit specs build the driver directly and stub the vmware-vra gem, which leaves a lot of code nobody runs: the plugin lookup that turns name: vra into this class, the config merging Test Kitchen does before the driver ever sees a value, required_config validation, the lazy defaults that need an instance to resolve, and every line of vmware-vra that turns a catalog request into HTTP and an HTTP response back into a Resource.

spec/integration

Loads a real kitchen.yml with the real loader, takes the driver Test Kitchen hands back, and runs create, status and destroy against a vRA stubbed at the wire with WebMock — which has been a development dependency all along without a single spec using it.

23 examples, covering a successful build, a deployment that reports CREATE_INPROGRESS before it finishes, a deployment holding resources that are not machines, a blueprint that builds two, a machine vRA reports no address for, a failed request, a deployment destroyed behind our back, and one offering no Delete action.

A vRA appliance cannot be stood up in a GitHub runner, but everything on this side of the socket can be, and now is, on every supported Ruby.

The rest

• kitchen.yml in the root, taking every setting from the environment so no site details or credentials land in the repo. It verifies over the transport, so a green kitchen test means the deployment came up and Test Kitchen could log in to it — which is the whole of what this driver is responsible for.
• A CI job running kitchen list and kitchen diagnose --all. That proves the gem is something the kitchen binary can find and load, that name: vra resolves to this driver, and that kitchen.yml is a config Test Kitchen accepts. Neither command contacts vRA.
• rake unit and rake integration, with rake test running both — so the shared lint-unit workflow picks up the integration specs with no change on its side.
• CONTRIBUTING gains what the two suites are for and how to run against a real appliance, and loses two instructions that were wrong: a spec path that does not exist (spec/kitchen/driver/vra_spec.rb), and a bare cookstyle that reports a hundred cookbook offenses on a gem.

bundle exec cookstyle --chefstyle, bundle exec rake test (55 unit + 23 integration), yamllint and markdownlint all pass.