attr_accessor is not needed because the methods are defined.
Cleaned up factories for classifications and their tag children.
Replace classification seeding with classification factory.

Added classification_department and classification_department_with_tags
factories.  Clarified the miq_host_provision_request_spec that used it
so we can better understand what it's different when there is only 1 tag
vs multiple tags.

Total time for these specs dropped from 8.79s to 3.75s. WAT
We shouldn't test the setup of the test.

Total time for this spec dropped from 27.18s to 23.41s. WAT
Merge pull request #911 from Fryguy/rm_classification_seed_in_specs

Remove Classification.seed in specs