Ping event should not trigger builds

While reviewing @bparees sample application I found out that he was triggering build with ping event, which is abiously wrong, I must have overlooked that case. So this PR extendeds integration tests with that test case and fixes it.
@bparees @mfojtik review pls.
So aren't we going to get notified when other things happen besides ping?  It might be better to list "all methods that should trigger a build" vs "all methods that won't"