Pre-release code cleanup

[Christianfoley]

Broadly improve code quality and cleanup remaining artifacts of local development:

• Restructure codebase into python project
• Modernize environment setup (oneshot via make)
• Populate README.md
• Add data population script, pulling from existing models & data in gdrive
• Remove hardcoded paths across the codebase
• Better module documentation
  • models
  • utils
  • data processing
  • scripts
• Remove redundant/deprecated code
  • Models
  • Utils
  • Scripts
• Add unit testing
  • Models
  • Utils
  • Dataset
  • Scripts