feature/maven - switching to Maven for dependencies, testing & ci, public artifact hosting

I've switched project to Maven. It will be way better to use Maven instead of Ant because of:

* Central artifact repository hosting: http://search.maven.org
* Integrated testing (I've added a sample test)
* Integration with CI (for ex.: travis ci on github, circleci etc.)
* Project structure and integration

BTW.: The code this client is poorly written, without test, and javadocs. It's a bit of pitty. Maybe you would like a help with it?

BTW.: I've prepared project to be published to Maven central repository. Here is the guide: https://docs.sonatype.org/display/Repository/Sonatype+OSS+Maven+Repository+Usage+Guide I can help you out with this, as well.