Bundled role? methods up into dynamic methods. Added an `affiliations_to_sym` method that converts affiliations into an array of symbols (because they can get saved as strings).
Added tests for the code I just pushed.
rspec keeps failing because of duplicate titles. This should fix it.
Added trustee? method to person.
Merge pull request #15 from biola/update_person

Bundled role? methods and added method to ensure affiliations are all symbols.