root/pypi: links for plover2cat

root/pypi plover2cat-3.1.0.tar.gz
root/pypi plover2cat-3.1.0-py3-none-any.whl
root/pypi plover2cat-3.1.0a0.tar.gz
root/pypi plover2cat-3.1.0a0-py3-none-any.whl