rust-numpy version 0.16.0
This release matches PyO3 version 0.16.0, adds support for object arrays, i.e. PyArray<PyObject, D>, contains a large overhaul of the dtype-related API, i.e. PyArrayDescr, by @aldanor and deprecates the npyiter module in favour of ndarray's iteration facilities. Smaller fixes and improvements are listed in the complete changelog.