I'm not entirely sure how this works, but CI was testing against the
updated Velopack package, whereas my local package was outdated and had
4 args.
Previous commit merges master to update the package version, this commit
fixes the args.
There are two primary paths here:
1. A user requests an update. The existing request is used if it's in
progress, or a new request is made and processed immediately.
2. Something is changed (e.g. the release stream) that triggers a
background request. A new request is made to run after the existing one.