pub fn tmp() -> io::Result<Config> {
        let tempdir = fallible!(tempdir::TempDir::new("sled_tmp"));

        Ok(Config {
            path: tempdir.path().into(),
            tempdir_deleter: Some(Arc::new(tempdir)),
            ..Config::default()
        })
    }
Returns a config with the `path` initialized to a system
temporary directory that will be deleted when this `Config`
is dropped.
src/config.rs