pythonPackages.pyscreenshot: add missing pillow dependency

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

@@ -6,6 +6,7 @@
 , entrypoint2
 , jeepney
 , mss
+, pillow
 }:
 
 buildPythonPackage rec {
@@ -20,6 +21,7 @@ buildPythonPackage rec {
   propagatedBuildInputs = [
     EasyProcess
     entrypoint2
+    pillow
   ] ++ lib.optionals (isPy3k) [
     jeepney
     mss
@@ -28,6 +30,8 @@ buildPythonPackage rec {
   # recursive dependency on pyvirtualdisplay
   doCheck = false;
 
+  pythonImportsCheck = [ "pyscreenshot" ];
+
   meta = with lib; {
     description = "python screenshot";
     homepage = "https://github.com/ponty/pyscreenshot";