Fix Code Coverage link

[Chessray]

codecov.io still seems to show the results for the default Gradle project. There's no mention of the classes currently in the project.

[jmprathab]

@Chessray Is this still requierd? I would like to work on this.

[Chessray]

Sure, feel free to take it. I see it more as an optional, but go ahead. 🙂