Make PGP signatures optional in desc files
repod/common/models.py: Change pgpgsig to Optional[str], as desc files may be created without the %PGPSIG% field.
repod/repo/package/syncdb.py: Move pgpsig in PACKAGE_DESC_VERSIONS from required to optional.
repod/templates/desc_v1.j2: Change template to only create and populate the %PGPSIG% field if pgpsig is not None.
tests/repo/package/test_syncdb.py: Add test case to test_package_desc_from_dict_derive_file_versions() to test the scenario in which no pgpsig is provided.
tests/test_convert.py:
Change test_file_data_to_model()
to include a test case in which only
the required fields are present (and no pgpsig).
Change test_repodbfile_render_desc_template()
to also include a case
in which pgpsig is not used.
Fixes #72 (closed)