The secrets loading algorithm has changed. We previously always loaded
config/secrets/secrets.json and loaded config/secrets-ENV.json.
The new loading algorithm is to treat config/secrets/secrets.json
as production only. This means it only gets loaded when NODE_ENV is
the string "production"
The config/secrets-ENV.json files moved to config/secrets/secrets-ENV.json
and will only be loaded when NODE_ENV is not "production".