Update README.md

Author: j5ik2o

README.md

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 This library provides an easy and simple way to handle Docker Container or Docker Compose on ScalaTest, based on [docker-java](https://github.com/docker-java/docker-java). The implementation of this library is thin, and if you know [docker-java](https://github.com/docker-java/docker-java), your learning cost will be negligible.