Created by: johnmeehan
Fixes #241 (closed)
Problem:
The selected value for a belongs to field was not shown to the user when editing a resource.
If a belongs to field has a selected value it will now be shown when the user goes to the edit page to make changes.
Solution:
use the selected field provided by options_for_select
options_for_select(field.associated_resource_options, field.data.try(:id))