hurl -o does not work

```
$ cd /tmp
$ ls test.tbz
ls: cannot access 'test.tbz': No such file or directory
$ hurl https://github.com/robur-coop/hurl/releases/download/v0.0.1_beta1/hurl-0.0.1.beta1.tbz -o test.tbz
hurl: option '-o': test.tbz already exist
Usage: hurl [OPTION]… URL [REQUEST_ITEM]…
Try 'hurl --help' for more information.
$ rm test.tbz
rm: remove regular empty file 'test.tbz'? y
```