loongson/pypi: links for ipypivot

loongson/mirror ipypivot-0.2.7.tar.gz
loongson/mirror ipypivot-0.2.6.tar.gz
loongson/mirror ipypivot-0.2.5.tar.gz
loongson/mirror ipypivot-0.2.4b0.tar.gz
loongson/mirror ipypivot-0.2.3b0.tar.gz
loongson/mirror ipypivot-0.2.2b0.tar.gz
loongson/mirror ipypivot-0.2.1b0.tar.gz