"Top N Slowest Example Group" from `--profile` does not account for time spent in `before(:context)` hooks
Created by: myronmarston
The implementation calculates the total example group time by summing the time of each individual example. Problem is, the time in before/after :context
hooks is not included in individual example times so it's completely ignored. This should be fixed, because if you are using :context
hooks it may be because of a slow operation and you wouldn't want it ignored when trying to find the slowest example groups.