Consider renaming oAuth Flows Object from 'flow' to 'flows'

[MikeRalphson]

This is probably a non-starter at this stage, but it is one of the rare examples in the specification of a singular noun being used to describe a collection. Changing this would draw attention to the fact this area of the specification has changed. See also #953 re: example/examples.

[ePaul]

I think now (before the final release of 3.0) is the perfect time to do this change.
Any implementer who has already implemented it as flow has a tiny change to do.

[webron]

It looks like an oversight and a remnant from the previous version. We'll consider it.