Automate indexing of Perl

[ranguard]

Perl doesn't get indexed correctly (so has to be done by hand https://github.com/CPAN-API/cpan-api/wiki/SysAdmin#how-to-index-the-latest-perl-release ) because...

20:49 @oalders we have to special case it because we can't just assume that the highest
version is the latest

http://www.cpan.org/src/README.html gets the order right... and the code is here:
https://github.com/perlorg/cpanorg/blob/master/bin/cpanorg_perl_releases

Need to update our code to use this.

[tsibley]

@ranguard @oalders Is the only reason this hasn't been automated the version sorting?

[oalders]

@tsibley not sure there's a specific reason this is stalled. Would be actually quite important to handle.