Replace tempdir with tempfile

Summary:
`tempdir` has been deprecated since 2018:
https://github.com/rust-lang-deprecated/tempdir/pull/46

It's functionality was merged into `tempfile` with minor tweaks:

- Methods names: `new` -> `with_prefix`, `new_in` -> `with_prefix_in`.
- `with_prefix_in`'s args order is reversed.
- Temp dirs no longer have a period between the prefix and the random
  name (before `foo.123abc`, now `foo123abc`).

Reviewed By: shayne-fletcher

Differential Revision: D50526255

fbshipit-source-id: bdb3b53a6b09a09c70c8e2533ad2cea46ee2842b

packer/src/main.rs

@@ -414,7 +414,7 @@ mod test {
             .join("src")
             .join("__fixtures__")
             .join("archive_a.tar");
-        let tmp_dir = tempdir::TempDir::new("manifest_test")?;
+        let tmp_dir = tempfile::TempDir::with_prefix("manifest_test.")?;
 
         let archive_paths = &[(&PackType::new("core"), artifact_path)];
         let path = manifest(archive_paths, &None, tmp_dir.path())?;