alternate implementation
try CPAN::ReleaseHistory for a spin
use JSON::PP for its in-coreness
use HTTP::Tiny instead of LWP
v0.10

  - use HTTP::Tiny instead of LWP
    the former being part of the core as of Perl 5.14
  - use JSON::PP instead of JSON
    the former being part of the core as of Perl 5.14
  - use CPAN::ReleaseHistory instead of BackPAN::Index
    the latter may (?) be faster,
    but the former has lighter set of prereqs