Fix depracation errors on rails 4
changed the has_many subjects association on the object
Fix roles lookup
Fix helpers test errors
Move completely to bundler
Sqlite3 gem name changed
There was one more method where the old join_table was being used.
Comparing `authorizable` prompts ActiveRecord to load it, each time individually. Eager loading could be employed, but I think an ID check is sufficient.
… (role -> subject)