Charlie Welsh

I've added tests for nested encoding, which is all I materially changed. I'm also happy to go write nested decode tests (though those just use Swift's standard `JSONDecoder`) if it...

@0xTim Following up on this — should I write more tests or do the ones I've added do the job?

I believe #207 would be solved by this PR (without the PostgresJSONCodable workaround)

Indentation should be fixed now

No, though this was over Live Share.