loongson/pypi: links for nbmerge

loongson/mirror nbmerge-0.0.4.tar.gz
loongson/mirror nbmerge-0.0.3.tar.gz
loongson/mirror nbmerge-0.0.2.tar.gz
loongson/mirror nbmerge-0.0.1.tar.gz
loongson/mirror nbmerge-0.0.1.dev0.tar.gz