Update requirements

[rossbar]

Synchronize requirements with main deepcell library and rm upper pins where possible.

[rossbar]

This is ready too - I'd definitely recommend including this prior to the next release since the scikit-learn pin is so old that it prevents pip from picking up wheels in some cases (e.g. Python 3.10).

FWIW the test suite passes with the removed pins, though there may be other sharp corners that aren't covered by tests. Running through any example notebooks with the proposed dependencies would be a good - any other ideas?

[rossbar]

I will self-merge to improve Python 3.10 support!