python{2,3}Packages.Pweave: fix build

Version 0.30 was missing the Python dependencies `nbconvert` and `markdown`.

Also Python 2 isn't supported any more since 0.30
(https://github.com/mpastell/Pweave/blob/master/CHANGELOG.txt) and can
therefore be dropped.

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

@@ -4,6 +4,9 @@
 , mock
 , matplotlib
 , pkgs
+, nbconvert
+, markdown
+, isPy3k
 }:
 
 buildPythonPackage rec {
@@ -15,8 +18,10 @@ buildPythonPackage rec {
     sha256 = "5e5298d90e06414a01f48e0d6aa4c36a70c5f223d929f2a9c7e2d388451c7357";
   };
 
+  disabled = !isPy3k;
+
   buildInputs = [ mock pkgs.glibcLocales ];
-  propagatedBuildInputs = [ matplotlib ];
+  propagatedBuildInputs = [ matplotlib nbconvert markdown ];
 
   # fails due to trying to run CSS as test
   doCheck = false;