Install patched fitsio package

There is a tiny bug in the published fitsio package which blocks INSTRM-632. A pull request has been submitted and informally accepted, but we need the fix now.

I have built a conda package tarball which installed OK at JHU. That can be copied and installed at Subaru and LAM. Yes, I should do it right with a conda-forge publication, etc. but do not want to learn how to do that just now.

The only significant dependency is numpy. I built against the current default of 1.21, but we have 1.20.3. Even though it is working fine I will rebuild against that.