Fix typo in association docs. Closes #3296.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3320 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* Fix typo in association docs. #3296. [Blair Zajac]
+
 * Fixed :through relations when using STI inherited classes would use the inherited class's name as foreign key on the join model [Tobias Luetke] 
 
 * MySQL: allow encoding option for mysql.rb driver.  [Jeremy Kemper]

activerecord/lib/active_record/associations.rb

@@ -125,7 +125,7 @@ def clear_association_cache #:nodoc:
     # === Association extensions
     #
     # The proxy objects that controls the access to associations can be extended through anonymous modules. This is especially
-    # beneficial for adding new finders, creators, and other factory-type methods that are only used as part of this associatio.
+    # beneficial for adding new finders, creators, and other factory-type methods that are only used as part of this association.
     # Example:
     #
     #   class Account < ActiveRecord::Base