apply check_dual_life_versions=0 to the case where the module does not exist in core at all at the starting_version
Dist-Zilla-Plugin-OnlyCorePrereqs-0.013

          - now treats dual-lifed modules that did not exist in core at all at
            the versions being checked against as the same as existing, but
            not being at a new enough version (relevant when
            check_dual_life_versions = 0)