Revert "Back to simple template type; hack around build dependency failing to load with cpanm"

This reverts commit e88e341563ce66af6a2a7eb0d44478c6d651545e.  Should
have fixed Template::Mustache error since
https://github.com/miyagawa/cpanminus/commit/306a26dbba81457f1523d8ef40ed313f18630b8a