Remove scikit-image from setup.py

[FredHappyface]

Would it be possible to remove scikit image from the setup.py as this prevents installation on python 3.9

Thank you

[addisonElliott]

👍 That's fine with me if you want to submit a PR.

[FredHappyface]

Brill thank you

Edit: Just submitted now - let me know if anything needs tweaking