Fix #518: undefined method `model_name`

A better solution by Gleb Mazovetskiy for issue #518 "undefined method
`model_name' for Ransack::Search" which affected Rails 4.2.1 and 5.0.0.

This fix allows us to remove the ActionView patch added 10 days ago in
Ransack 1.6.4.

Closes #518.

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Change Log
 
+## Unreleased
+### Fixed
+*   A better fix for the "undefined method `model_name' for Ransack::Search"
+    issue [#518](https://github.com/activerecord-hackery/ransack/issues/518)
+    affecting Rails 4.2.1 and 5.0.0. This fix allows us to remove the
+    ActionView patch in Ransack version 1.6.4.
+
+    *Gleb Mazovetskiy*
+
+
 ## Version 1.6.5 - 2015-03-28 - Rails 5.0.0 update
 ### Added
 

lib/ransack/naming.rb

@@ -20,6 +20,10 @@ module Ransack
     def to_model
       self
     end
+
+    def model_name
+      self.class.model_name
+    end
   end
 
   class Name < String