loongson/pypi: links for elasticdl-preprocessing

loongson/mirror elasticdl_preprocessing-0.2.0rc3.tar.gz
loongson/mirror elasticdl_preprocessing-0.2.0rc3-py3-none-any.whl
loongson/mirror elasticdl_preprocessing-0.2.0rc2.tar.gz
loongson/mirror elasticdl_preprocessing-0.2.0rc2-py3-none-any.whl
loongson/mirror elasticdl_preprocessing-0.2.0rc1.tar.gz
loongson/mirror elasticdl_preprocessing-0.2.0rc1-py3-none-any.whl