Implement more best practices for the API

[mrchrmn]

following the suggestions outlined in this article:
https://blog.devgenius.io/best-practice-and-cheat-sheet-for-rest-api-design-6a6e12dfa89f

[medic-code]

A small win might be versioning the API, so that if there are breaking changes, large API updates and can ensure backward compatability in the future.

Worth a discussion on what would constitute a change in API version.