fix(pubsub): Don't log all pubsub events (#524)

We're now logging all pubsub events in AbstractNotificationAgent;
given the volume of these events, turn off this logging for pubsub.

echo-notifications/src/main/groovy/com/netflix/spinnaker/echo/notification/AbstractEventNotificationAgent.groovy

@@ -53,7 +53,7 @@ abstract class AbstractEventNotificationAgent implements EchoEventListener {
 
   @Override
   void processEvent(Event event) {
-    if (log.isDebugEnabled() && mapper != null) {
+    if (log.isDebugEnabled() && mapper != null && !event.getDetails().getType().equals("pubsub")) {
       log.debug("Event received: " + mapper.writerWithDefaultPrettyPrinter().writeValueAsString(event))
     }