attempt to resolve issues on travis - keep pty alive for the lifetime of the process
avoid reporting a module twice, if it appears in more than one phase
Dist-Zilla-Plugin-PromptIfStale-0.029

          - ensure @INC does not become mangled during tests
          - use newer Dist::Zilla::Util::AuthorDeps to avoid using Path::Class
install our dist just as Dist::Zilla's .travis.yml does
dump dzil build log too; show full output even if success
install new Carp to get around issue #368