Deprecate validation_data_hsc and validation_data_decam and remove any references to them from current stack packages. There should be very few, but I saw at least one in faro. Follow the procedure documented in the dev guide.
This is the implementation ticket for RFC-815.
Change CalibrateTask refcat defaults to Gaia DR2 for astrometry and PS1 for photometry
Move validation_data_hsc and validation_data_decam to legacy
Deprecate and remove validation_data_hsc and validation_data_decam
krughoff: do you mind doing this medium-sized review? It's mostly deleting files and lines that reference these two packages, plus making notes in their readme files. I removed a few references to validation_data_hsc from faro, and some validate_drp-related things from lsst_ci: I hope the validation group is ok with those changes?
I have small changes requested in the faro package, but seems fine otherwise.