Deprecate ksonnet and use python/golang to submit jobs

[Jeffwan]

Ksonnet has been deprecated for long time but we are still using it in testing flow.

The next step is

1. Use python/golang to render testing job template.
2. Find alternative to render argo workloads
3. Simplify e2e testing tech stack and remove ksonnet dependencies.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.