Don't build test suite by default.

Former-commit-id: 1c4aa04eab09b40ab9c0a56fe452f92a152c2146

reanimate.cabal

@@ -36,6 +36,11 @@ Source-Repository head
     Type:      git
     Location:  git://github.com/lemmih/reanimate.git
 
+Flag test
+  Description: Enable testing (requires stack)
+  Default:     False
+  Manual:      True
+
 library
   hs-source-dirs:     src
   default-language:   Haskell2010
@@ -98,6 +103,9 @@ test-suite spec
   other-modules:
     UnitTests
   hs-source-dirs: test
+  if !flag(test) {
+    Buildable: False
+  }
   build-depends:
     base,
     directory,