Refactor and cleanup rubocop issues on classification_spec.rb

https://bugzilla.redhat.com/show_bug.cgi?id=1157942
Removed updating categories so users can redefine the defaults

https://bugzilla.redhat.com/show_bug.cgi?id=1157942
Refactor Classification seeding and add tests

https://bugzilla.redhat.com/show_bug.cgi?id=1157942
Merge pull request #1112 from gmcculloug/classification_seeding

Classification seeding