Fix typo: has -> hash

Author: jdufresne

activerecord/test/cases/fixtures_test.rb

@@ -1727,7 +1727,7 @@ def test_composite_identify_hashes_to_same_values_based_on_position_in_key
 
       assert_equal id, id_hash_two.values.first
       assert_equal id, id_hash_three.values.first
-      assert_equal id_has_two.values, id_hash_three.values.slice(0, 2)
+      assert_equal id_hash_two.values, id_hash_three.values.slice(0, 2)
     end
   end
 end