As requested by the reviewer PR updated in order to fix API duplication and missing https for hubblesite.

Added YTS API in Video Category

Add Twelve Data API (finance section)

Added Satellite Passes API

Update Vector Express to match v2.0

Move CONTRIBUTING.md to the root folder

Add NBP (National Bank of Poland) currency exchange rates API

Add VALR (Cryptocurrency Exchange in South Africa) API

Update the link of Launch Library 2 to its homepage for APIs

Add Foreca Weather API

Added IP2WHOIS API

Changed waifu.pics url

changed to to api docs in stead of main page

Added QWeather in README.md

Add catAPI

Added Visual Crossing Weather API

Russian State Duma Open Data

Added Dark Souls 3 API

Adds shrtlnk.dev url shortener

Add localizr API

Add a RESTful free API to check the weather

Add 'User-Agent' to the auth_keys array in the validate_format script

Add BigDataCloud API for IP and Geolocation

Added Etsy API

Adds Humble Bundle API

Bump httplib2 from 0.18.0 to 0.19.0 in /build

Add Spoonacular Food API

Added zip codes and streets from Brazil API

Update to Meteorologisk Institutt API.