buildbot: add Python 3 support

pkgs/development/python-modules/buildbot/pkg.nix

@@ -0,0 +1,24 @@
+{ lib, buildPythonPackage, fetchPypi, setuptools }:
+
+buildPythonPackage rec {
+  pname = "buildbot-pkg";
+  version = "1.4.0";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "06f4jvczbg9km0gfmcd1ljplf5w8za27i9ap9jnyqgh3j77smd7a";
+  };
+
+  postPatch = ''
+    # Their listdir function filters out `node_modules` folders.
+    # Do we have to care about that with Nix...?
+    substituteInPlace buildbot_pkg.py --replace "os.listdir = listdir" ""
+  '';
+
+  meta = with lib; {
+    homepage = http://buildbot.net/;
+    description = "Buildbot Packaging Helper";
+    maintainers = with maintainers; [ nand0p ryansydnor ];
+    license = licenses.gpl2;
+  };
+}