feat: implement the driver status hook

[tas50]

kitchen list could only report what the state file remembered, because Kitchen::Driver::Base#status was never overridden.

def status(state)
  return super unless state[:deployment_id]

  deployment = lookup_deployment(state[:deployment_id])
  return super unless deployment
  ...
end

vRA is now asked directly, so a deployment that failed to build, is still building, or was destroyed from the vRA console shows its real state without a converge.

live is true only for CREATE_SUCCESSFUL, matching Vra::Deployment#successful?. CREATE_INPROGRESS and CREATE_FAILED report live: false but keep their own name, which distinguishes "not ready yet" from "will never be ready" — a distinction a bare boolean loses.

Falling back rather than failing

kitchen list should not raise on a driver it is only interrogating, so the base "unknown" answer covers: no deployment in state, vRA answering Vra::Exception::NotFound (a real answer — the deployment is gone), and vRA being unreachable. lookup_deployment rescues ::StandardError, with the leading :: because Kitchen::StandardError would otherwise win lexical lookup inside module Kitchen and narrow the rescue to Test Kitchen's own errors.

Verification

• rake test — 55 examples, 0 failures (48 before; 7 new), rake exit 0
• cookstyle --chefstyle — 5 files, no offenses
• yard stats — 100% documented