If you delete a project, `each :refresh` doesn't treat downstream projects as having changed

[drewinglis]

If you have two projects, project-a and project-b, and project-a depends on project-b, and you delete project-b but don't remove the dependency from project-a on project-b, running:
lein monolith each :refresh build install, e.g., won't build project-a.

I imagine this is because lein monolith treats project-b as an external dependency, but if you had the refresh history I would think we could correctly identify this.