Return callback test text if event is a callback test

Author: jyoung488

app/controllers/callbacks_controller.rb

@@ -10,9 +10,9 @@ def create
     event_type = event[:event][:event_type]
     id = event[:signature_request][:signature_request_id]
 
+    return "Hello API event received" if event_type == "callback_test"
+    
     case event_type
-    when "callback_test"
-      p "Hello API event received"
     when "signature_request_sent"
       Sign.create(signature_request_id: id,
         status: 'Sent')