After upgrading to 3.2 and pushing to heroku... heroku logs shows after starting up unicorn:

gistfile1.txt

2013-07-25T12:14:15.425902+00:00 app[web.1]: DEPRECATION WARNING: 
You have Rails 2.3-style plugins in vendor/plugins! Support for these plugins will 
be removed in Rails 4.0. Move them out and bundle them in your Gemfile, or fold them 
in to your app as lib/myplugin/* and config/initializers/myplugin.rb. See the release 
notes for more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. 
(called from <top (required)> at /app/config/environment.rb:5)

2013-07-25T12:14:15.425283+00:00 app[web.1]: DEPRECATION WARNING: You have Rails 2.3-style 
plugins in vendor/plugins! Support for these plugins will be removed in Rails 4.0. 
Move them out and bundle them in your Gemfile, or fold them in to your app as 
lib/myplugin/* and config/initializers/myplugin.rb. See the release notes for more on 
this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. 
(called from <top (required)> at /app/config/environment.rb:5)