Fix authentication.

After grading from the pre-node-specific version, authentication broke for me.
I traced it to this issue.

I think the old syntax used for 'request' may have not have been valid.
While I see in the `request` docs the use of `.form`, I don't see it
documented in combination with the callback.

In any case, the syntax for calling `request` works now.

Note that the expected args pasted to `request.host` and the
undocumented `requestHandler` were not the same before, and they remain
different after this change. I would expect the `requestHander` should
accept the same arguments as `request` but am not changing it here in
case someone is using this undocumented feature outside of the test
suite. That should potentially be updated as well for consistency.

Also, while looking at `request`, you may wish to bump the dependency up to 2.39.0
in package.json.
Merge pull request #78 from markstos/fix-passing-arguments-to-request

Fix authentication.