Reorganize project

[alichtman]

• all src files should go in a shallow-backup dir.
• Split up the large main file into multiple smaller files.
  • git.py (All git methods)
  • config.py (All config related methods)
  • backup.py (All backup related methods)
  • reinstall.py (All reinstallation methods)
  • printing.py (All printing methods)
• Make sure all tests work
• Finish Add config paths to config file #128 and remove backup_paths_temp.py
• Make sure all the pypi things still work.
  • py_modules and entry_points need a close look in setup.py

[alichtman]

Working branch: https://github.com/alichtman/shallow-backup/tree/reorganize