Add migration for watermarks
Add migration for watermarks

nathanbwright/exercism.io,treiff/exercism.io,RaptorRCX/exercism.io,tejasbubane/exercism.io,jtigger/exercism.io,nathanbwright/exercism.io,tejasbubane/exercism.io,treiff/exercism.io,nathanbwright/exercism.io,tejasbubane/exercism.io,jtigger/exercism.io,jtigger/exercism.io,mhelmetag/exercism.io,RaptorRCX/exercism.io,treiff/exercism.io,nathanbwright/exercism.io,jtigger/exercism.io,mhelmetag/exercism.io,mhelmetag/exercism.io,tejasbubane/exercism.io,treiff/exercism.io,mhelmetag/exercism.io,RaptorRCX/exercism.io,RaptorRCX/exercism.io