build: build using the oldest supported version of numpy, for python version
build: build using the oldest supported version of numpy, for python version

Binaries compiled with old Numpy versions are ABI compatible with
newer Numpy versions, but not vice-versa.

To avoid running issues into on cedar, we should build using the oldest
compatible numpy version. We can then run packages using whatever newer
Numpy version we want.

Conversation here: https://github.com/radiocosmology/draco/pull/145

radiocosmology/draco,radiocosmology/draco