Report when Github rate limit is telling you < 10 left

Was adding everyone to my project when suddenly I got rate limited.

https://api.github.com/rate_limit was at zero.

If I had known, I wouldn't have been using the command the same way. I would have edited the file manually to keep my existing Github rate for important things like lookup.

I think a warning when you're down to your last 10 requests would be helpful.