Expire ApplicationStatus after a given time-to-live

[oyvindio]

Currently FIAAS keeps the last 10 ApplicationStatus resources for each Application. When running in a cluster with many applications there quickly ends up being a lot (thousands) of resources. I think it is mostly the last 2 or 3 statuses that are relevant in practice. Statuses are less relevant the older they are.
Maybe it makes sense to implement a more advanced cleanup policy where FIAAS deletes ApplicationStatus resources that are older than some duration, and only keeps maybe the last 2 or 3 for each application?