static RxDockerClient fromDefaultEnv(){
  return newDockerClient(System.getenv("DOCKER_HOST"),System.getenv("DOCKER_CERT_PATH"));
}

static RxDockerClient fromDefaultEnv ( ) { return newDockerClient ( System . getenv ( "DOCKER_HOST" ) , System . getenv ( "DOCKER_CERT_PATH" ) ) ; }
builds the client using docker_host and docker_cert_path environment variables
