[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POller has been replaced by Notifier which returns a channel of events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/kubernetes.go

@@ -0,0 +1,12 @@
+package client
+
+// Kubernetes client
+type Kubernetes interface {
+	// UpdateDeployment patches deployment annotations with new metadata
+	UpdateDeployment(string, interface{}) error
+}
+
+// Metadata defines api request metadata
+type Metadata struct {
+	Annotations map[string]string `json:"annotations,omitempty"`
+}