Fix Julia 1.8

[PallHaraldsson]

No description provided.

[PallHaraldsson]

I see a similar change in #15, already approved. It may be better to not allow older the CxxWrap. I'm not sure, either should work for 1.8, and possibly my way is better for the future for older Julia versions? Anyway please merge either and tag a new release.

[archit120]

Hey, @PallHaraldsson

Thank you for your contribution, I really do not have the bandwidth to manage this project anymore. Would you be willing to take over as maintainer?

[PallHaraldsson]

I don't actually use this project so I'm not sure what I'm getting into (though I did look a bit into the project before). I think I might still be qualified enough, and if not could pass it off to someone else if I realize I'm not, maybe back to you. I'm very interested in machine learning, both for NLP (e.g. transformers, that are also taking over computer vision) and otherwise. I'm actually not sure OpenCV is the future of CV, I could take over maintenance, not sure it's a huge burden. Do you think we would need to talk much about it (face to face) before you decide, or I could ask you questions after, if I need to?