Refuse to clone if the path already exists

Dependencies

• [2] LYTVEPH3 Avoid cloning into an existing path
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• edit in pijul/src/commands/clone.rs at line 55
  [4.184550]

  [2.0]
  +

  + if std::fs::metadata(&path).is_ok() {

  + bail!("Path {:?} already exists", path)

  + }