[WIP] K8s update and runtime package changes (#895)

* First commit: outline of K8s runtime package

* Added poller. Added auto-updater into default runtime

* Added build and updated Poller interface

* Added comments and NewRuntime that accepts Options

* DefaultPoller; Runtime options

* First commit to add Kubernetes cruft

* Add comments

* Add micro- prefix to K8s runtime service names

* Get rid of import cycles. Move K8s runtime into main runtime package

* Major refactoring: Poller replaced by Notifier

POller has been replaced by Notifier which returns a channel of events
that can be consumed and acted upon.

* Added runtime configuration options

* K8s runtime is now Kubernetes runtime in dedicated pkg. Naming kung-fu.

* Fix typo in command.

* Fixed typo

* Dont Delete service when runtime stops.

runtime.Stop stops services; no need to double-stop

* Track runtime services

* Parse Unix timestamps properly

* Added deployments into K8s client. Debug logging

runtime/kubernetes/client/watch/watch.go

@@ -0,0 +1,26 @@
+package watch
+
+import "encoding/json"
+
+// Watch ...
+type Watch interface {
+	Stop()
+	ResultChan() <-chan Event
+}
+
+// EventType defines the possible types of events.
+type EventType string
+
+// EventTypes used
+const (
+	Added    EventType = "ADDED"
+	Modified EventType = "MODIFIED"
+	Deleted  EventType = "DELETED"
+	Error    EventType = "ERROR"
+)
+
+// Event represents a single event to a watched resource.
+type Event struct {
+	Type   EventType       `json:"type"`
+	Object json.RawMessage `json:"object"`
+}