功能： ################### 运行该Dockerfile构建的image时，容器中的sshd服务会自动启动。如果将工程中files目录下的文件替换成你的机器的公共ssh key，你的机器可以无密访问该容器。只对root用户有效。

function: ################### ssh service of container will automatic startup if you use image of this project generate. additional，if you replace files/id_rsa.pub with public ssh key of your machine， you will access this container not need password through ssh. just for root user.

usage: ################### clone this project, use public ssh key of your machine replace files/id_rsa.pub and build docker image.

colorscode/sshd