message: Remove src_files and remove_file
  They only apply to the main source archive and their role can be
  fulfilled through the skip argument of add_archive too.
diff: @@ -61,19 +61,6 @@ fn new(sess: &'a Session, output: &Path, input: Option<&Path>) -> Self {
  }
  }
  - fn src_files(&mut self) -> Vec<String> {
  - self.entries.iter().map(|(name, _)| String::from_utf8(name.clone()).unwrap()).collect()
  - }
  -
  - fn remove_file(&mut self, name: &str) {
  - let index = self
  - .entries
  - .iter()
  - .position(|(entry_name, _)| entry_name == name.as_bytes())
  - .expect("Tried to remove file not existing in src archive");
  - self.entries.remove(index);
  - }
  -
  fn add_file(&mut self, file: &Path) {
  self.entries.push((
  file.file_name().unwrap().to_str().unwrap().to_string().into_bytes(),
  