Auth test errors in node >8

[wesleytodd]

The tests on the 5.x branch were failing in node>8 because digest is now required. This fixes that missing argument.

[wesleytodd]

@dougwilson Is there a reason we still have both a 5.x and a 5.0 branch? This happens every time I pick back up some of these PRs I have, and I can never remember why we have both and which is meant for what. #3218 was against 5.x, as are many others, but the main PR is 5.0. Is this PR pointless because I should have been rebasing to 5.0?

[dougwilson]

The {major}.x branches point to whatever the most recent tagged commit is on that major while branches that are {major}.{minor} are release branches for staging that specific release.

[dougwilson]

All of this should be documented in https://github.com/expressjs/express/blob/master/Release-Process.md

[dougwilson]

Looks like the CI failed and this doesn't merged into the 5.x branch without conflicts. I think this underlying issue was already fixed, though.

[wesleytodd]

Yeah I think I will just close this. I will make the new PR for that feature against 4.x and then see if this comes up again as I port it to the 5.0.