Access to rate limit headers for the current API call

[jschuur]

For something that makes heavy use of the Twitch API, it would be useful to see the rate limit headers for the last API call made.

The rate limits are pretty generous, but I am running into a situation where I make a lot of frequent API calls across lots of channels and I don't have a sense of how close I am getting to the 800 points/minute quota e.g., even when I batch multiple channels together.