Prout can be very chatty when a project has many microservices (checkpoints)

Prout was a bit too chatty with this project with 9 microservices:

https://github.com/guardian/grid/pull/2570

![image](https://user-images.githubusercontent.com/52038/57855605-eaf8d100-77e2-11e9-8d06-1ab95928055b.png)

Maybe Prout could only write a comment when _all_ checkpoints are seen?