Error importing "nyc_collision_kibana.json" to saved objects

[ginosian]

In the readme file for "nyc_collisions" it is suggested to import "nyc_collision_kibana.json".
Latest version of kibana doesn't support json for saved objects, any attempt to convert it to .ndjson fails as kibana still not able to read the content.
Please would you uodate the repository and provide working .ndjson files?