DDPB-1125 - upgrades: ruby -> 2.4  gems sass -> 3.4.25, scss_lint -> 0.54.0
DDPB-1125 - upgrades: ruby -> 2.4  gems sass -> 3.4.25, scss_lint -> 0.54.0

ministryofjustice/opg-digi-deps-client,ministryofjustice/opg-digi-deps-client,ministryofjustice/opg-digi-deps-client,ministryofjustice/opg-digi-deps-client