tests: added one test for decompress without --dir

[venoosoo]

Adds a test for decompressing without --dir/-d by using .current_dir()
instead, covering a gap noted in #958 (comment)

[marcospb19]

Hi! Thanks for the test.

Possibly due to some recent changes it's now failing with this message:

---- decompress_into_cwd stdout ----

thread 'decompress_into_cwd' (1864790) panicked at tests/utils.rs:72:49:
called `Result::unwrap()` on an `Err` value: Custom { kind: NotFound, error: Error { kind: ReadDir, source: Os { code: 2, kind: NotFound, message: "No such file or directory" }, path: "/tmp/.tmpaIVyCN/after/before" } }


failures:
    decompress_into_cwd

Could you check if that's a problem with the test or the new version of ouch? thanks!