GOTO astrometry tools

• gen_xmatch - cross-matching tool with catsHTM, implemented from main gotophoto repo,
• fit_astrom_simult - robust astrometric tweaks for improving an initial solution
• framescore - QA tool, test version is included in refit_wcs.py
• Example scripts using all of the above

Dependencies:

• catsHTM with local copies of the catalogs you want to cross-match against. Currently set for using Gaia DR2.
• If you aren't on the GOTO or CSC systems, set the environment variable CATSHTM_PATH to point to the catalog path.

Quickstart:

• In the scripts folder, refit_wcs.py will apply all the tools in goto-astromtools on the frame that will be applied in the pipeline version, and output a new frame with updated WCS and photometry table.