Parameterized training script, comet integration, refined evaluation script

[alexbarnett12]

I have made a plethora of updates to the original FastDepth scripts to adapt them to our use cases. This includes:

• Training script (not included in forked FastDepth repo)
• JSON selection of hyperparameters
• Training script modularization for reusability
• Comet ML Experiment integration
• Comet Optimizer integration
• Utility functions for depth visualization, comet logging, model saving
• Refined evaluation script