Add some conifguration and logging for the hub

registrar/internal/services/pubsub.go

@@ -0,0 +1,14 @@
+package services
+
+type Publisher interface {
+	Publish(topic string, message string)
+}
+
+type PubSub interface {
+	Publisher
+	Subscriber
+}
+
+type Subscriber interface {
+	Subscribe(topic string) <-chan string
+}