Delete addons (#9209)

* Delete addons

* Remove ReactFragment dependency from tests

* Remove addons testing from fixtures

* Don't mention createFragment() in a warning

* Address feedback

* Remove unused variables

* Remove mention of deleted file

* Add a missing key to the test

* Fix lint

Rakefile

@@ -37,8 +37,6 @@ task :update_hashes do
   map = {
     'react.js' => 'dev',
     'react.min.js' => 'prod',
-    'react-with-addons.js' => 'addons_dev',
-    'react-with-addons.min.js' => 'addons_prod',
     'react-dom.js' => 'dom_dev',
     'react-dom.min.js' => 'dom_prod',
     'react-dom-server.js' => 'dom_server_dev',