New orderbook-transitive-test.js demonstrates RIPD-639

Reviewers: @JoelKatz @ximinez
Well, note that this path is not, in fact, taken, because we haven't fixed the bug yet.  Right now we get zero paths but when it's fixed we'll get a path.

But - good idea!  I'll put my best guess as to what the result should actually be, and when we actually fix the bug, we can at least use that as a starting point...