python3: Add makeshift django3 package till there's an official one.

pkgs/django3/default.nix

@@ -0,0 +1,28 @@
+{ stdenv, buildPythonPackage, fetchPypi, substituteAll,
+  isPy3k,
+  asgiref, pytz, sqlparse
+}:
+
+buildPythonPackage rec {
+  pname = "Django";
+  version = "3.0.2";
+
+  disabled = !isPy3k;
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "1jjih2x6kyp89kc5p98f30pm2isc2phf35qdhs9hhf8i3vw7adcc";
+  };
+
+  propagatedBuildInputs = [ asgiref pytz sqlparse ];
+
+  # too complicated to setup
+  doCheck = false;
+
+  meta = with stdenv.lib; {
+    description = "A high-level Python Web framework";
+    homepage = https://www.djangoproject.com/;
+    license = licenses.bsd3;
+    maintainers = with maintainers; [ ];
+  };
+}

pkgs/nixpkgs.nix

@@ -11,6 +11,7 @@ in {
       theme_flat-remix = callPackage ./flat-remix { };
       theme_sddm_midnight = callPackage ./sddm_midnight { };
       xdiskusage = callPackage ./xdiskusage { };
+      django3 = pkgs.python3Packages.callPackage ./django3 { };
     };
   };
 }

pkgs/pkgsets/python3.nix

@@ -9,7 +9,7 @@ in {
     bpython
     # cairosvg cairocffi
     configparser
-    django
+    pkgs.django3
     emoji
     epc
     flake8