Enable BLACK by default
Enable BLACK by default

Reviewed By: zertosh

Differential Revision: D30368884

fbshipit-source-id: 0db919765a0d91f7592d09ad924768d14ed5ce12

facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst