root/pypi: links for mnist2

root/pypi MNIST2-2.0.3.tar.gz
root/pypi MNIST2-2.0.2.tar.gz
root/pypi MNIST2-2.0.1.tar.gz
root/pypi MNIST2-2.0.0.tar.gz
root/pypi MNIST2-1.0.0.tar.gz