Reference data: Zenodo

Any simulation should have reference cases so that a check can be made that the executables and libraries are generally working OK. Gemini reference data is automatically downloaded when a test is about to be run by CMake. If for some reason the reference data becomes unavailable, Gemini will work but won't have the ability to check its correctness until reference data is again provided.

The gemini/scripts/meson_run_test.py script has the URLs to this data.