Disable simplejson test on Darwin otherwise build fails.

pkgs/development/python-modules/simplejson/default.nix

@@ -1,12 +1,14 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, stdenv
 }:
 
 buildPythonPackage rec {
   pname = "simplejson";
   version = "3.10.0";
   name = "${pname}-${version}";
+  doCheck = !stdenv.isDarwin;
 
   src = fetchPypi {
     inherit pname version;
@@ -25,4 +27,4 @@ buildPythonPackage rec {
     homepage = http://code.google.com/p/simplejson/;
     license = lib.licenses.mit;
   };
-}
+}