When checking the required status checks we currently get all statuses
and get the successful of them. However Github returns all historic
status changes there. So a change that get a successful check, then a
recheck and then a failed check still enters the gate but will be
prohibited by Github to merge in the end. However github also offers
us a combined status call that only returns the current state of the
statuses. Using this fixes the issue.
Change-Id: Iec3b2a3dfc8626870381604badd40de71e7257b9
9fa93fdefa