Update README.md about validateStatus (#2912)
Update README.md about validateStatus (#2912)

Rewrote the comment from "Reject only if the status code is greater than or equal to 500" to "Resolve only if the status code is less than 500"
mzabriskie/axios,mzabriskie/axios,axios/axios,axios/axios,axios/axios,mzabriskie/axios