python27Packages.application: 2.7.0 -> 2.8.0 and fix build

The build is currently broken due to failure to build `darcs` to fetch the src
package. The homepage is already their GitHub repo, and it appears to be the
active src of development anyways. See NixOS#83718

I came across this while debugging this failure:
https://hydra.nixos.org/build/115510612

Note that the `application` dependency *does* succeed on Hydra, because it's
already on local disk in Hydra's store, but I cannot rebuild locally because it
has prefer local builds.
https://hydra.nixos.org/build/115512559

This package is not reproducible on 20.03 or buildable outside of Hydra, so I
intend to backport the fix.

CC @NixOS/nixos-release-managers

ZHF: NixOS#80379

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

@@ -1,21 +1,26 @@
-{ lib, buildPythonPackage, fetchdarcs, zope_interface, isPy3k }:
+{ lib, buildPythonPackage, fetchFromGitHub, zope_interface, isPy3k }:
 
 buildPythonPackage rec {
   pname = "python-application";
-  version = "2.7.0";
+  version = "2.8.0";
   disabled = isPy3k;
 
-  src = fetchdarcs {
-    url = "http://devel.ag-projects.com/repositories/${pname}";
+  src = fetchFromGitHub {
+    owner = "AGProjects";
+    repo = pname;
     rev = "release-${version}";
-    sha256 = "1xpyk2v3naxkjhpyris58dxg1lxbraxgjd6f7w1sah5j0sk7psla";
+    sha256 = "1xd2gbpmx2ghap9cnr1h6sxjai9419bdp3y9qp5lh67977m0qg30";
   };
 
   buildInputs = [ zope_interface ];
 
+  # No tests upstream to run
+  doCheck = false;
+
   meta = with lib; {
     description = "Basic building blocks for python applications";
-    homepage = https://github.com/AGProjects/python-application;
+    homepage = "https://github.com/AGProjects/python-application";
+    changelog = "https://github.com/AGProjects/python-application/blob/master/ChangeLog";
     license = licenses.lgpl2Plus;
   };
 }