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.
This was likely introduced with the refactor to make ColorSchemeColor a database object. Add a test so this doesn't happen again.
Also test other basics of the WizardSerializer.
For some reason, the .as_json left Ruby objects in; I solved this with a round trip through JSON during the test.