Make config parameters optional

[rr83019]

closes #105

[hrj]

I was able to get it to work after some trial and error:

When using Option for extraction, we need to use java types instead of scala types. So this works:

case class ConfigField(
                        port: Option[Integer],
                        address: Option[String],
                        throttle: Option[Integer],
                        seed: Option[Integer],
                        captchaExpiryTimeLimit: Option[Integer],
                        threadDelay: Option[Integer],
                        boolTest: Option[java.lang.Boolean],
                        corsHeader: Option[String],
                        maxAttempts: Option[Integer]
                      )

Needs to be converted to the correct Scala type later. So I did this hack:

 case class ConfigField(
  port: Option[Integer],
  address: Option[String],
  throttle: Option[Integer],
  seed: Option[Integer],
  captchaExpiryTimeLimit: Option[Integer],
  threadDelay: Option[Integer],
  boolTest: Option[java.lang.Boolean],
  corsHeader: Option[String],
  maxAttempts: Option[Integer]
) {
  val portInt = port.map(_ + 0)
  val boolTestBoolean = boolTest.map(_ || true)
}

...

  val fields = configJson.extract[ConfigField]

  val port1: Int = fields.portInt.getOrElse(8888)
  val address1: String = fields.address.getOrElse("0.0.0.0")
  val boolTest: Boolean = fields.boolTestBoolean.getOrElse(true)