loongson/pypi: links for xgboost-ranking

loongson/mirror XGBoost-Ranking-0.7.1.tar.gz
loongson/mirror XGBoost-Ranking-0.7.0.tar.gz
loongson/mirror XGBoost_Ranking-0.7.0-py2-none-any.whl
loongson/mirror XGBoost-Ranking-0.6.1.tar.gz
loongson/mirror XGBoost_Ranking-0.6.1-py2-none-any.whl