launchpad: Add missing copyright headers

swh/lister/launchpad/tests/conftest.py

+# Copyright (C) 2020  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
 from swh.lister.core.tests.conftest import *  # noqa
 from datetime import datetime
 import json

swh/lister/launchpad/tests/test_lister.py

+# Copyright (C) 2020  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+
 def test_launchpad_lister(lister_launchpad, datadir):
 
     lister_launchpad.run()