pythonPackages.pycontracts: Move to own file

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

@@ -0,0 +1,21 @@
+{ stdenv, buildPythonPackage, fetchPypi
+, nose, pyparsing, decorator, six }:
+
+buildPythonPackage rec {
+  pname = "PyContracts";
+  version = "1.7.9";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0rdc9pz08885vqkazjc3lyrrghmf3jzxnlsgpn8akl808x1qrfqf";
+  };
+
+  buildInputs = [ nose ];
+  propagatedBuildInputs = [ pyparsing decorator six ];
+
+  meta = with stdenv.lib; {
+    description = "Allows to declare constraints on function parameters and return values";
+    homepage = https://pypi.python.org/pypi/PyContracts;
+    license = licenses.lgpl2;
+  };
+}