Fix missing json import
Add robot length
Update mapper to create more efficient file formats.

- Replace json output with png and numpy binary
- Instead of 4 2d arrays create 1 single 1d array
Update pathfinder to load image instead of json
Remove load grid data func
Add directory path to files in config
Update code to account for config file change
Fix image write bug where wrong image written
Minor spacing fix
Add particle filter parameters
Add initial particle filter class, implement sense with lookup table