Emit pod k8s events

[hidalgopl]

Currently user sees only one event if the pod was scheduled successfully: ProviderCreateSuccess comparing to Scheduling -> Scheduled -> Pulling -> Pulled -> Running feedback from pod running on not virtual nodes.

Another useful feature from user experience standpoint would be sending informations about cell state changes during provision to kip stateful set.

There is some work started on branch https://github.com/elotl/kip/tree/k8s-events

You may see there's a event record function added. One thing to keep in mind is that you need to convert kip objects into the k8s ObjectReference type, so the emitted event is linked with corresponding k8s object.