Fix the version in sufia-models.gemspec so you can bundle install
Added attr_accessible

This gives us a place to list attributes that should be accepted for
updating other than GenericFile#terms_for_editing. This is important in
the case of nested attributes, where terms_for_editing contains
":creator", but the attributes coming off the form look like:
"creator_attributes" => { "name" => "Penelope", "role" => "Director"}
Merge pull request #141 from projecthydra/acceptable_properties

Added attr_accessible