Created by: gracewashere
Problem:
When a belongs_to relationship was defined with a custom class_name,
Administrate wouldn't pick up on the option and would try to fetch the
object using the relationship name. This resulted in 500 errors, most
commonly on form pages.
See https://trello.com/c/hkZynxwL
Solution:
Let the user pass a class_name option to the Administrate
field to override the default class lookup.
The solution is essentially what we did for has_many relationships
back in 092d55f2.