Added Complete Experimentation Tracking.

[osoblanco]

Added Complete Experimentation Tracking using Aim. Visualizations of trackables added to Readme.

Now you can:

1. Track all the model hyperparameters and architectural choices used when creating the model.
2. Track all types of losses.
3. Filter all the experiments with respect to hyperparameters or the architecture
4. Group and aggregate w.r.t. all the trackables to dive into granular experimentation assessment.
5. Track the validation audios to track how the model improves.
6. Track the Weight and Gradient distribution over training.

[osoblanco]

@ming024 please take a look at your earliest convenience :) . Any suggestions for improvements are also greatly welcome.