cpants has the following minor issues that need to be checked out
has META.json - but I have the [MetaJSON] directive in my dist.ini file and the build produces it. Maybe it gets fixed in the next upload to CPAN?
same thing with META.yml
Repository plugin for Dzil should take care of the other
check http://www.cpantesters.org/distro/A/Astro-Constants.html?grade=3&perlmat=2&patches=2&oncpan=2&distmat=2&perlver=ALL&osname=ALL
http://cpants.cpanauthors.org/dist/Astro-Constants