Wrong value propagated to `Rx.now` in `Obs`

[lihaoyi]

Wrong value propagated to `Rx.now` in `Obs`

[Voltir]

So yea, 103 shouldnt happen because v2() should always equal v3() -- when these things actually evaluate, a priority queue of nodes to visit is set up, and I noticed something strange, starting here:

https://github.com/lihaoyi/scala.rx/blob/master/scalarx/shared/src/main/scala/rx/Rx.scala#L121

I think this following constraint should be true:
assert(min.depth >= currentDepth, "What?")
And indeed, when the (0,17) case occurs, it is true, but when then (0,103,17) it ends up being false! Have I forgotten how priority queues are supposed to work? Im pretty sure the repeated calls to deque should end up outputting in sorted order and values shouldn't "go backwards" like it appears to be doing.

@lihaoyi any ideas?