SQLite for standalone deployments?

[sebpuetz]

Diesel doesn't seem to support multiple DB backends with a single implementation

1. duplicate DB code for SQLite?
2. Rewrite DB module with sqlx

SQLite schema will have to differ from the postgres schema (e.g. different types) and should probably differ in terms of structure (registering voice servers doesn't make much sense), so giving 1. a shot before tearing it out might make sense