adjust CLI; add tests.
fix artifact collection; add tests.
add tests for readers.
add tests for zippers.
fix parameter order; update example.
update .gitignore.
adjust tests; add full check/upgrade tests.
move check logic into own namespace; create utils namespace.
refactor options and utils; add upgrade tasks.
implement testing.
fix testing.
add message after upgrade.
flush after ':print'.
fix documentation.
add docstrings to CLI flags.
implement get/latest; fix tests.