Update numjs 0.16.0 to fork ac7df3c

As numjs is unmaintained, this fork allows it to build on modern npm and
adds support uint 64-bit integer types based on PRs that were merged
into upstream dependencies.

Fork: https://github.com/aschampion/numjs
Commit: ac7df3cdd2ee999a1f676ac2a0982d63c85527da