add the file before allowing the role

Dist::Zilla::Role::FileInjector, before 5.000, did
$file->meta->get_attribute('added_by') which does not work if the role has
been applied (it should have done find_attribute_by_name)
Dist-Zilla-Role-File-ChangeNotification-0.003

          - test fixed to work around a use of the file metaclass in older
            Dist::Zilla::Role::FileInjector