Throw exception when 'relatedModels' association not found
Throw exception when 'relatedModels' association not found

Borrows same exception/message from core as a more helpful alternative to:

    Fatal error: Call to a member function name() on null

simkimsia/crud,dakota/crud,davidyell/crud,FriendsOfCake/crud,FriendsOfCake/crud-json-api,ankr/crud,johanmeiring/crud,pwerken/cakephp-crud,bravo-kernel/crud,ojengwa/crud