Removes unused factory for non-existent model AdminUser.
Changes how JS and CSS are included (a.k.a. registered) for ActiveAdmin.
Renames some files.
Adds RandomRecord module, which adds a `.random` method to classes
to return a random record from the databse.
Adds method User#last_name_first.
Adds tests for User.random and Org.random.
Adds :with_items and :with_collabs traigs to the :custom_collection factory.
Simplifies :admin factory.
Changes Faker data in Org factory.
Removes TestHelper, duplicates functionality of WarningSupressor.
Changes DatabaseCleaner settings in before/after hooks.
Changes the admin form for CustmCollections, specifically with CustomCollectionImages and Owner fields.
Reorganizes specs for admin a little bit.
Merge pull request #382 from afred/fix-376

Fix 376