It would be helpful to be able to pass in the rm option when performing a BuildImageCmd, for the same reasons @alexec made the change [here](https://github.com/alexec/docker-java/blob/1b0beeec3e198b68a756b2141c36d12678a609e5/src/main/java/com/kpelykh/docker/client/DockerClient.java#L852).
