Revert ".travis.yml: deactivate 5.8 because of to old CPAN"
Revert ".travis.yml: deactivate 5.8 because of to old CPAN"

This reverts commit 570dc1cecfc2a415de63f9eeed3b5ef59e24e2b6.
Since List::MoreUtils::XS is now official release, we can built tests upon it without tricking around.

Signed-off-by: Jens Rehsack <69d49c504a9219a55b8be0f905e8fe3c32ffb57f@netbsd.org>

perl5-utils/List-MoreUtils