How to test locally?

I've tried:

```bash
$ docker run --rm -it -e SU_PASSWORD=postgres -e OPERATOR_PASSWORD=postgres -e REPL_PASSWORD=postgres -e PRIMARY_REGION=iad image locally-built-image
```

but I am getting:

```
panic: failed to set directory ownership: failed to set directory ownership: exit status 1

goroutine 1 [running]:
main.panicHandler({0xa0d220, 0xc00028e010})
/go/src/github.com/fly-apps/fly-postgres/cmd/start/main.go:190 +0x4a
main.main()
/go/src/github.com/fly-apps/fly-postgres/cmd/start/main.go:67 +0xe65
```

What is this referring to?