Use HttpClient and RateLimiter to force consumers to respect the api rate limits

[chinwobble]

System.NET.HTTP.HttpClient provides a higher level abstraction on web requests that allows you to more easily inject custom logic such as rate limiting, and default headers in the request pipeline.

See below for an example of its usage.
https://raw.githubusercontent.com/chinwobble/CommonServices/master/src/WebAccessService/Common/RateLimitHandler.cs