refactor integration tests to run in parallel

Improve driver none stop to work on older systems

hyperv: Powershell was not found in the path 

This reverts commit 9daa3d3e.

Apparently make hates target names with colon in them, so avoid that.
Seems like we are not using $(REGISTRY), so avoid trying to pull it.

First try the local images, then try to pull from the registry...
If not found in either place, then build a tag a new local image.

We downgraded the kernel (to 4.15) in 2be51dc6,
but never updated the Makefile from 4c4cd31b...

The default kernel in Buildroot 2018.05.x was
4.16.13, but upgraded in Minikube to 4.16.14

It's not needed since nginx 0.20.0.

See the following pull-requests for context:
* https://github.com/kubernetes/ingress-nginx/pull/3126
* https://github.com/kubernetes/ingress-nginx/pull/3156