This new unit test highlights an unexpected behavior of the issuing
controller: the issuing controller is updating the certificate's status
when the certificate request has a failure ("Reason = Failed"), but the
controller might have picked up an out-of-date certificate request.
The consequence is that the issuing controller would set the certificate
to "Issuing = False". That happens when a re-issuance is triggered with
an old failing certificate request.
Signed-off-by: Maël Valais <mael.valais@gmail.com>