ministryofjustice/atet — pull request #402 by stevegraham (2014-11-25 14:02:21+00:00)
Title: Claim#increment_fee_group_reference!

Replicates Jadu mechanism for incrementing FGRs to allow user
to retry payment after unsuccessful transaction.

Pads the FGR in place with "-1" and increments the pad subsequent times