You advise to "fork it", but immediately after that you add the notorious "do not write your own" meme. Can you see the inconsistency of the messages?
Part of security is being up-to-date in regards to things like hashes. If authors don't update their own libraries and you need to tweak them manually, how is it different from "writing your own"?
I agree I'm a bit inconsistent, but the library is well written, and exchanging the hashing function is a trivial task. That's not really quite "writing your own". I just mean to discourage people who aren't 100% sure they know what they're doing.
I strongly agree with Armin: HMAC-SHA1 (note, the combo, it's not just the latter) is still good security for most applications you'd consider this library for.
Part of security is being up-to-date in regards to things like hashes. If authors don't update their own libraries and you need to tweak them manually, how is it different from "writing your own"?