Campaign doesn't auto-archive once funds are spent

[coderberry]

User Story

As an advertiser, when my total budget is spent on a campaign, the campaign should be archived.

Why Is this Needed?

When the campaign runs out of funds, we have to pay out all extra ad displays that happen on this campaign.

Description

Type: Bug

[coderberry]

This appears to be related to us using Redis as the method of determining when the funds are spent.

This will require us to revise the way we do campaign limits.