Cabal revisions of shake-ext-2.7.0.3

Hackage metadata revisions edit the .cabal file after upload; each diff below is one revision.

 cabal-version: 1.18 name: shake-ext version: 2.7.0.3+x-revision: 1 license: BSD3 license-file: LICENSE copyright: Copyright: (c) 2018 Vanessa McHale         shake -any,         composition-prelude,         directory -any,-        Cabal >=2.0,+        Cabal >= 2.0 && < 2.2,         template-haskell -any          if flag(development)