Add mandatory "perl" META field
Add mandatory "perl" META field

The `perl` field specifies the minimal perl version for which this distribution can be installed and is a mandatory field. The value of `"6.*"` indicates any version suffices.

It is recommended to use [Test::META](https://modules.perl6.org/repo/Test::META) module as an author test, to catch any issues with the META file.
skids/perl6sum