python-packages: click 3.3 -> 4.1

pkgs/top-level/python-packages.nix

···
   };
 
   click = buildPythonPackage rec {
-    name = "click-3.3";
+    name = "click-4.1";
 
     src = pkgs.fetchurl {
       url = "https://pypi.python.org/packages/source/c/click/${name}.tar.gz";
-      sha256 = "1rfn8ml80rw3hkgpm1an5p3vdyhh7hzx4zynr8dhfl7bsw28r77p";
+      sha256 = "1n4fvxpgbna83g6daarscljwpbarr45qfalh9hqla8ayy84ysfg3";
     };
 
     meta = {