drop t/os/mac.t, per rt#83318

See https://rt.cpan.org/Public/Bug/Display.html?id=83318 for the full
discussion, but basically this test is failing everywhere that is Linux (at
least), and is not needed anymore as classic mac support has been dropped.
Changelog
Reset canonical repository in metadata
Remove Module::Install::PAR
Update MANIFEST/MANIFEST.SKIP
Update .gitignore
Version 0.15