title: AWS CDK Autoscale group LifecycleHook does not notify on initial startup
body: <p>I have wired up an lifecycle hook to an ec2 autoscale group for both launching and terminating actions.  The notification is supposed to go SNS topic that then triggers a lambda.  On first startup of the autoscaling group (going from 0 to 1 instance), I only receive notification with event = &quot;autoscaling:TEST_NOTIFICATION&quot;.  I do not receive the expected launch event.  However, if I terminate an instance and allow the autoscaling group to recreate the ec2 instance, the launch event fires perfectly (same for the termination event).</p>
  <p>Is it expected that the initial scale up would not generate an event?  If not, any suggestions on how I can troubleshoot this?  I don't see anything in any logs that might point to the problem.</p>