- #831
- #709

There's something appealing about switching to Rails' built in `Single
Table Inheritance` for `Furniture`, rather than our flyweight registry;
but I also know that STI can be a bit of a smell...

Anyway, now when you call `Marketplace.all` and get *only*
`Marketplace`s. Maybe someday we'll pull this up in to the `Furniture`
classes responsibilities so we don't have to do it on every single piece
of Furniture...