Correctly expose Browser asset map files
Correctly expose Browser asset map files

Tell web browser to look for map files relative to served CSS/JS. That
should respect Browser mount point.

Closes #954

arkency/rails_event_store,RailsEventStore/rails_event_store,RailsEventStore/rails_event_store,arkency/rails_event_store,arkency/rails_event_store,RailsEventStore/rails_event_store,arkency/rails_event_store,RailsEventStore/rails_event_store