ec4c0737 

Add a type for `Dependencies`

It’s just a `Map`, but it gets used often enough that it makes sense.
Time to Start Worker time Duration Time to finish
Config 1s 1s 1s 2s
Eval 3s 6s 6s 10s
Build 11s 1m11s 1m15s 1m26s
Suite 1s 1m19s 1m25s 1m26s