need later version of ::Role::PPI for the "require" fix

e.g.  http://www.cpantesters.org/cpan/report/2ae7c959-6bf9-1014-962c-8478a06e0af6
-- PPI::Document is being properly loaded as of
https://github.com/rjbs/Dist-Zilla/commit/07df47a7b3
Dist-Zilla-Plugin-Keywords-0.004

          - bump dependency on Dist::Zilla to get a minor fix in the PPI role