python2Packages.ecpy: unbreak due to invalid code

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

@@ -9,11 +9,17 @@ buildPythonPackage rec {
     sha256 = "9635cffb9b6ecf7fd7f72aea1665829ac74a1d272006d0057d45a621aae20228";
   };
 
+  prePatch = ''
+    sed -i "s|reqs.append('future')|pass|" setup.py
+  '';
+
   propagatedBuildInputs = lib.optional (!isPy3k) future;
 
   # No tests implemented
   doCheck = false;
 
+  pythonImportsCheck = [ "ecpy" ];
+
   meta = with lib; {
     description = "Pure Pyhton Elliptic Curve Library";
     homepage = "https://github.com/ubinity/ECPy";