fix: Set archive directory size to zero. (#27)

Fixes problem with extracting the custom "empty template".

src/init.rs

@@ -598,6 +598,7 @@ impl TemplateBuilder {
  let mut header = Header::new_gnu();
  header.set_entry_type(EntryType::Directory);
  header.set_path(path)?;
+ header.set_size(0);
  header.set_mtime(mtime);
  header.set_mode(0o775);
  header.set_uid(1000);