Prone to updates.

• [x] /user/{uid} - User endpoint

• [ ] /hackstead/{uid} - Hackstead endpoint | Returns all information and data associated with a user's hackstead.

• [ ] /possesion/{id} - Gets information about a given entity ('gotchi, item, etc.)

(taken from github/hackagotchi/backend#1) (Update 2020-06-21: GET user is implemented)