We were calling `dup` on the hash and using that to check for changes. However, we were not duplicating the values, so changes to arrays or nested hashes would not be detected.
It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
