Adds validation for User#bio.
Fixes OpenvaultAsset#create_relations_from_pbcore!
Reworks test for Openvault::Pbcore#ingest! -- a little less DRY, but more explicit, and clearer imho.
Adds ActiveFedora::TestCleaner, taken from https://github.com/projecthydra/curate/blob/435fc011be5c13e5fdd8586549aae4ef80e7e010/spec/support/active_fedora/test_cleaner.rb