Cleanup cloud functions

@mhahn Do we want to save the list of users that are part of the lending circle on the parentGoal? we have a property for this called users https://github.com/CodePath-MAF/SharedAssets/blob/master/schemas.md#goal

This may come in handy when we are handling push notification after saving a post, as the parent goal will have the list of all users we would need to send notifications to.