Lua has just a single structure, namely a table, which is used for both
lists and maps. This poses a problem when a list is empty, because it's
not able to distinguish between the 2, and will default to a map.

This implementation:

* Defines the exact structure
* Writes out json and yaml at the same time
* Fetches release, instead of statically defining it in-line

And because it's statically built, has no dependencies except musl.

See: alpine/infra/docker/secdb#2