Fixed cabal check error

Hackage expects all packages to have bounds attached to `base`.

Author: coot

quickcheck-monoids/quickcheck-monoids.cabal

@@ -20,7 +20,7 @@ common warnings
 library
     import:           warnings
     exposed-modules:  Test.QuickCheck.Monoids
-    build-depends:    base,
+    build-depends:    base >=4.14 && <4.21,
                       QuickCheck
     hs-source-dirs:   src
     default-language: Haskell2010