bump QuickCheck upper bound

tasty-hspec.cabal

@@ -31,7 +31,7 @@ library
     hspec ^>= 2.11.0,
     hspec-api ^>= 2.11.0,
     hspec-core ^>= 2.11.0,
-    QuickCheck ^>= 2.7 || ^>= 2.8 || ^>= 2.9 || ^>= 2.10 || ^>= 2.11 || ^>= 2.12 || ^>= 2.13 || ^>= 2.14,
+    QuickCheck ^>= 2.7 || ^>= 2.8 || ^>= 2.9 || ^>= 2.10 || ^>= 2.11 || ^>= 2.12 || ^>= 2.13 || ^>= 2.14 || ^>= 2.15,
     tasty ^>= 1.3 || ^>= 1.4 || ^>= 1.5,
     tasty-smallcheck >= 0.1 && < 0.9,
     tasty-quickcheck ^>= 0.9.1 || ^>= 0.10,