root/pypi: links for cubic

root/pypi cubic-0.7.0a1.tar.gz
root/pypi cubic-0.7.0a1-py3-none-any.whl
root/pypi cubic-0.6.0.tar.gz
root/pypi cubic-0.6.0-py3-none-any.whl
root/pypi cubic-0.5.0.tar.gz