Released rust-numpy 0.3

I just released the version 0.3.0 of rust-numpy, which provides bindings to numpy C API.

It’s the first version after we migrated to pyo3 from
rust-cpython , and it includes lots of API changes.

So any feedback or contribution is really welcome!
If you find some APIs hard to use, or want some additional features, please don’t hesitate to open issues :blush: