Updates the pod status in Kubernetes to "Failed" when the pod status is
not found from the provider.
Note that currently thet most providers return `nil, nil` when a pod is
not found. This works but should possibly return a typed error so we can
determine if the error means not found or something else... but this
works as is so I haven't changed it.
* Add k8s.io/client-go/tools/cache package
* Add cache controller
* Add pod creator and terminator
* Pod Synchronizer
* Clean up
* Add back reconcile
* Remove unnecessary space in log
* Incorprate feedbacks
* dep ensure
* Fix the syntax error
* Fix the merge errors
* Minor Refactor
* Set status
* Pass context together with the pod to the pod channel
* Change to use flag to specify the number of pod sync workers
* Remove the unused const
* Use Stable PROD Region WestUS in Test
EastUS2EUAP is not reliable