Clojurians Log v2

@alexmiller In a ticket from clojure.data.json I saw you mentioned: > Can you switch from using hash-map when constructing the option maps to array-map? If it's not already faster now, it likely will be in 1.11 Is there more info on why array maps would be faster in 1.11? Interested!

There were some changes as part of the trailing map stuff and I think Rich and Fogus had ideas about more, but I’m not sure where all that landed