Add set require
Created by: ineverov
Add require 'set' and remove to_set method calls per https://github.com/rspec/rspec-core/commit/d8af26ebbd10bbe65182ff4aa4e575cdfa779386#commitcomment-861297
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Created by: ineverov
Add require 'set' and remove to_set method calls per https://github.com/rspec/rspec-core/commit/d8af26ebbd10bbe65182ff4aa4e575cdfa779386#commitcomment-861297