Fix error saying severity is missing (#2516)
Fix error saying severity is missing (#2516)


JoshuaKGoldberg/tslint,berickson1/tslint,berickson1/tslint,berickson1/tslint,palantir/tslint,andy-ms/tslint,palantir/tslint,IllusionMH/tslint,andy-ms/tslint,mprobst/tslint,mprobst/tslint,JoshuaKGoldberg/tslint,JoshuaKGoldberg/tslint,IllusionMH/tslint,andy-hanson/tslint,IllusionMH/tslint,andy-hanson/tslint,mprobst/tslint,andy-hanson/tslint,palantir/tslint,andy-ms/tslint