v0.0.0-1597347308

clean up k8s worker

* no more unnecessary logging
* default to LAN worker, allow k8s worker override
* turns out we don't need to do anything with the error stream besides open it
* pull the determining of k8s-related defaults out of `main.go`

* if we can be a bit more careful with our tests, we should actually be able
  to remove the K8sConnection type and replace it with a rest.Config, where
  getting the URL path to a portforward action should be a matter of calling
  rest.RESTClientFor and then using the fluent APIs, as is currently hidden in
  the implementation of systemK8sConnection.

Signed-off-by: Jamie Klassen <[email protected]>