[ ] Lazy-load the file (required for walt.*.setup, as config file does not exist at setup-time).
[ ] Check config file (is "walt-net" configured? Is the fields' value acceptable? Etc.)
[ ] Support YAML-based config. Structure & values should match those of JSON format, so that code does not need to be changed but in the loading part (walt/server/conf.py). Note that YAML supports comments.
Configuration loading may need to be reworked:
walt.*.setup, as config file does not exist at setup-time).walt/server/conf.py). Note that YAML supports comments.