How to do recursive tests with M::B 0.34?

[Elliot Shank]

This works with 0.33 but fails with 0.34 because the test_files() parameters 
are directories:

   sub ACTION_authortest {
       my ($self) = @_;

       $self->test_files( qw< t xt/author > );
       $self->recursive_test_files(1);

       $self->depends_on('test');

       return;
   } # end ACTION_authortest()

Given the documentation for test_files(), the 0.34 behavior is correct.  I 
could invoke find_test_files() myself, but that isn't public API.  Is there a 
simple way of doing this?