Integrate osu!Data on Docker

[Eve-ning]

Motivation

The key problem we face when training opal is the manual work preparing data to train our model.
This heavily slows down experimentation, updating, and thus, increases workload.

One of our key recent advances is the development of osu! Data on Docker.
This wraps the data we retrieve from data.ppy.sh in Docker, which abstracts away the technical details and provides us with a simple docker compose up to boot a MySQL instance of the data.

Given Docker, we can further wrap the training, evaluation, monitoring script in it.

Major Changes

• Integrates osu-data-docker submodule into the pipeline
• Wraps training into Docker
• Restructure and refactor project to be neater