Add overall rank column (#5)

* Add overall rank column.
* Write errors to `stderr`.
* Add space between each score and each ranking (`[1, 3]` instead of `[1,3]`).
* Add weekly scheduled builds.
* Rename app published executables to desired ones, to avoid manual edition before publishing.

Add support for Arena tournaments (#2)

* Add support for Arena tournaments
* Add Scores column

Release initial version of both library and app (#1)