Optional sql support for Docker/Docker-Compose

[therealkevinard]

sqlite support does require a larger image and build time, but certainly has its benefits vs fs.

The repository should provide optional support for smoother on-boarding for those who prefer a sql-backed solution.

[titpetric]

Could you build this with alpine, both for the builder and the final images? apk add sqlite and a particular symlink should be enough to create a CGO build, and then just install this into the final image too - possibly deleting the sqlite cli client to save a few bytes. (RUN apk add sqlite && rm /usr/bin/sqlite or whatever the path in the final image)