Since it's a developer release, you won't get it if you upgrade in CPAN or CPANPLUS. You have to download and install manually.

actually you can just use CPAN:

$ cpan
cpan[1]> ls andya
[...]
  117943 2007-09-03 ANDYA/Test-Harness-2.99_01.tar.gz
[...]
cpan[2]> install ANDYA/Test-Harness-2.99_01.tar.gz
[download]