Add in kubernetes test to native image build

[James Roper]

Right now, we only test the native image build against the TCK, we don't test actually running it in Kubernetes. This means a bunch of things don't get exercised:

• Kubernetes cluster bootstrap
• Remoting
• Serialization of remotely sent messages

I'm 110% positive that the current native image build therefore won't work in Kubernetes.

We already have the minikube smoke tests, we should use that, but we should do a little more than what they currently do:

• Scale up to multiple nodes.
• Run a few more tests to ensure serialization of all messages sent over remoting works.

[Adriano Santos]

I would recommend start the minikube with more than one node as below and running the cluster tests:

minikube start --driver kvm2 --memory 8g --cpus 4 --nodes 3