pythonPackages.keystoneauth1: fix missing argparse dep

pkgs/development/python-modules/keystoneauth1/default.nix

@@ -0,0 +1,27 @@
+{ buildPythonPackage, isPyPy, fetchPypi, python
+, pbr, testtools, testresources, testrepository, mock
+, pep8, fixtures, mox3, requests-mock
+, iso8601, requests, six, stevedore, webob, oslo-config
+}:
+
+buildPythonPackage rec {
+  pname = "keystoneauth1";
+  version = "1.1.0";
+  name = "${pname}-${version}";
+  disabled = isPyPy; # a test fails
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "05fc6xsp5mal52ijvj84sf7mrw706ihadfdf5mnq9zxn7pfl4118";
+  };
+
+  buildInputs = [ pbr testtools testresources testrepository mock
+                  pep8 fixtures mox3 requests-mock ];
+  propagatedBuildInputs = [ iso8601 requests six stevedore
+                            webob oslo-config ];
+
+  postPatch = ''
+    sed -i 's@python@${python.interpreter}@' .testr.conf
+    substituteInPlace requirements.txt --replace "argparse"
+  '';
+}