Check `perl` version

[zoffixznet]

Don't see if it does it already in code.... I notice some user put "perl": "6", which is after 6.c and any other version we release. Since the field specifies the minimum perl version for the module, such modules would be uninstallable once our module installers actually care about that attribute.

[jonathanstowe]

I'm not sure what the test should be though

 $ver < v6 && $ver >= v6.c

but then other things could pass that. Or just

$ver.parts[0] == 6 && $ver.parts.elems == 2

I'll have a think during the hackday at work tomorrow :)