Update Kubernetes APIs for 1.16

[nicknezis]

Various Kubernetes APIs were deprecated in 1.16. The various Heron Kubernetes yamls (and maybe code?) need to be updated to use the newer APIs. Kubernetes documentation on the changes can be found here: https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/

Example line that needs to be updated:

incubator-heron/deploy/kubernetes/helm/templates/tools.yaml

Line 31 in d8db1c5

apiVersion: extensions/v1beta1

[joshfischer1108]

@nicknezis any chance you could open up a PR to address these issues?

[nicknezis]

I've started the work. Also updating code to solve #3259

[nicknezis]

I bumped the API up from 1.0.0-beta3 to 3.0.0. I'm currently working on and testing a fix to use the latest 6.0.1. But this has more API changes so will take slightly longer.

[nicknezis]

This was completed by #3426