Support for dead resolver to run outside of a Kubernetes cluster

[vivintw]

Hi @sercand , This is a great little project, I was thinking of writing something similar from scratch before I found this project.

Would it be possible to add a deadResolver to the kubernetes resolver ?

this will help folks who want to run their gRPC client outside Kubernetes for testing

[sercand]

Hi @vivintw, I would happy to review and merge the PR