Working challenge

ExampleRoute.scala

case req@ Post -> Root / "challenge" =>
      val body = req.body.collect {
        case c: BodyChunk => new String(c.toArray)
      }.toTask

      body.flatMap{ s: String =>
        if (!s.startsWith("go")) {
          Ok("Booo!!!")
        } else {
          Ok(emit(s) ++ repeatEval(body))
        }
      }