python3Packages.django_2_2: init at 2.2.1

This introduces Django-2.2, the new LTR version of django.

For the time being, django-1.11 continues to be LTR in nixpkgs
django-2.2 is introduced to prepare the migration.

pkgs/development/python-modules/django/2_2.nix

@@ -0,0 +1,38 @@
+{ stdenv, buildPythonPackage, fetchPypi, substituteAll,
+  isPy3k,
+  geos, gdal, pytz, sqlparse,
+  withGdal ? false
+}:
+
+buildPythonPackage rec {
+  pname = "Django";
+  version = "2.2.1";
+
+  disabled = !isPy3k;
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "1spa701phl8ha7qmfr89hwpa43kf52zbrs3xyc0rlvxianykrk3g";
+  };
+
+  patches = stdenv.lib.optional withGdal
+    (substituteAll {
+      src = ./1.10-gis-libs.template.patch;
+      geos = geos;
+      gdal = gdal;
+      extension = stdenv.hostPlatform.extensions.sharedLibrary;
+    })
+  ;
+
+  propagatedBuildInputs = [ 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; [ georgewhewell lsix ];
+  };
+}

pkgs/top-level/python-packages.nix

@@ -2433,6 +2433,8 @@ in {
     gdal = self.gdal;
   };
 
+  django_2_2 = callPackage ../development/python-modules/django/2_2.nix { };
+
   django_1_8 = callPackage ../development/python-modules/django/1_8.nix { };
 
   django-allauth = callPackage ../development/python-modules/django-allauth { };