Include Change log in Readme

[pietrygamat]

The change log on https://marathontesting.com/ is not up to date, and the one in the codebase is not immediately accessible. It might be useful to have it linked to from the readme on the repo landing page.

[pietrygamat]

I'd also appreciate little convieniences like ready to copy-paste Maven/Gradle coordinates visible in the front page.

<dependency>
    <groupId>com.jaliansystems</groupId>
    <artifactId>marathon-java-driver</artifactId>
    <version>5.4.0.0</version>
    <scope>test</scope>
</dependency>

Comming from the user of previous version of Java driver, deciding if it is worth upgrading right now.

[kdmurthy]

Thanks for the feedback and PR. Shall get to it soon.