Whenever somebody creates an Application, we want them to be automatically subscribed to it so that we don't get any orphaned applications. So if we receive a FactSheetCreatedEvent for an Application fact sheet, this handler creates a RESPONSIBLE subscription for the user who created the fact sheet. Note that we don't add a subscription if the acting user is in the exception list.
def handle(self, event, fact_sheet, **kwargs):
Called automatically whenever a FactSheetCreated or FactSheetUpdated event comes in via webhook.