Support ndarray 0.16

[magnusuMET]

Fixes #438

[magnusuMET]

This PR is blocked on rust-ndarray/ndarray-linalg#379

[bluss]

Previous discussion about ndarray 0.16, rust-numpy and ndarray-linalg: rust-ndarray/ndarray#1374

[bluss]

Ok, that comment was maybe not super helpful - ndarray 0.16 got a few more changes since that happened. But I think it points out that ndarray-linalg doesn't need to be a strict blocker for this update.

[magnusuMET]

I see the main argument: Allow the deprecation and let the end user deal with the dependency through their lockfile. I am not sure how to create a lockfile with the right dependency through cargo invocations, but checking in the lockfile should hopefully work

[bluss]

Some more deprecated methods were removed in ndarray post adamreichold's test.
I would suggest maybe restricting to ndarray 0.15 and 0.16 if possible (this is not my project -- just how I would do it); I don't usually work with open ranges of dependencies so don't really know.

Hoping ndarray-linalg can be tested using ndarray 0.15 only suggested. With that said, we should be able to get a solution (to update) ndarray-linalg sooner or later..