rel_dir deprecated

I have errors trying to start lutim, Mojo complains about rel_dir deprecated in lib/Mounter.pm .

I'm in no way a perl expert, or Mojo, but I took some time to read the documentation and I think you can change the use of rel_dir with child().

For example, line 29 of lib/mounter.pm could be

my $theme = $self->home->child('themes', $config->{theme});

More infos here http://mojolicious.org/perldoc/Mojo/File#child