python3Packages.xcffib: fix tests

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

@@ -3,6 +3,7 @@
 , fetchPypi
 , xorg
 , cffi
+, nose
 , six
 }:
 
@@ -22,6 +23,10 @@ buildPythonPackage rec {
 
   propagatedBuildInputs = [ cffi six ];
 
+  checkInputs = [ nose ];
+
+  pythonImportsCheck = [ "xcffib" ];
+
   meta = with stdenv.lib; {
     description = "A drop in replacement for xpyb, an XCB python binding";
     homepage = "https://github.com/tych0/xcffib";