Speed up development by only reloading classes if dependencies files
This can be turned off by setting config.reload_classes_only_on_change
to false.
Extensions like Active Record should add their respective files like db/schema.rb and db/structure.sql to config.watchable_files
if they want their changes to affect classes reloading.
Thanks to https://github.com/paneq/active_reload and Pastorino for the inspiration. <3
https://github.com/rails/rails/commit/fa1d9a884c0d5b70c97442e3360ac98ca5fa4340