Implement kubernetes driver

[glyn]

A kubernetes driver would run the invocation image in kubernetes, probably as some kind of job with cluster admin privileges.

Note that the image would not have access to a docker daemon.

This should provide a workaround for the problem of needing to patch ~/.kube/config for Docker Desktop. See #762 for context.

[radu-matei]

We did start some efforts in #560 for Duffle, and https://github.com/deislabs/cnab-operator is an operator implementation that is very much in progress (and would really benefit from some contributions 😅)

[glyn]

Thanks @radu-matei! #560 is currently giving HTTP 500, but hopefully it will come back next week.

[radu-matei]

Try https://github.com/deislabs/duffle/pull/560/files, this seems to work for me.

[jlegrone]

I've been working on a k8s driver implementation that leverages the Job object (this gives us free retry and timeout logic). I wasn't aware of #560, but I think what I have is at feature parity. Can this issue be assigned to me for now?

[radu-matei]

@jlegrone - sure!
That being said, I'd like to further explore the choice to use a Job.