Turning in create a simple JSON API assignment.

Turning in create a simple JSON API assignment.
Thank you for your review. Added range checks.
https://github.com/HIROSN/sea-b24-simple-express-json-api/commit/a5647fca14b9ea029209c6c5cb3272360847a3c5

https://travis-ci.org/HIROSN/sea-b24-simple-express-json-api/builds/41561080