Use Gradle as Build tool.

Hey Luan,

It is a good idea to use Gradle as a build tool. In order to use it, I had to move some files to different directories. 
I also removed the binary (compiled) and the jar files. The compiled files can be built on your own machine, and the jar files are going to be managed by Gradle, which will download them for us!

Now, you can compile and run the tests anywhere: any SO, any IDE, or even better, from the command line! hehe ;)

Take a look on the commits. You should approve them!

=]
Portela