The fix for
DM-11332 adds a Butler policy-like construct called "writeRecipe", which is a nested dictionary that must conform to a schema. The current verification iterates over keys & values in a loop that IMO will be hard to extend and debug. I'd like to add a schema validation tool to do this work instead. I'd like to Cerberus (http://docs.python-cerberus.org/en/stable/) for that, but would be open to other suggestions as well.