Demo example doesn't work

Version `0.21.0`.

If I copy/paste this [demo](https://github.com/http4s/rho/blob/master/examples/src/main/scala/com/http4s/rho/swagger/demo/Main.scala) to a sbt project I get the following error:

```
object ui is not a member of package com.http4s.rho.swagger
```

Edit: Code in the [tutorial](https://github.com/http4s/rho/blob/master/Rho.md) also seems to be broken... 