Cabal revisions of ShellCheck-0.7.2

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

 Name:             ShellCheck Version:          0.7.2+x-revision: 1 Synopsis:         Shell script analysis tool License:          GPL-3 License-file:     LICENSE     location: git://github.com/koalaman/shellcheck.git  library+    build-depends: mtl <2.3+     hs-source-dirs: src     if impl(ghc < 8.0)       build-depends: