Merge pull request #26619 from maclover7/jm-a502703c-notes

Add info about a502703c to Rails 5 release notes

guides/source/5_0_release_notes.md

@@ -595,6 +595,9 @@ Please refer to the [Changelog][active-record] for detailed changes.
 *   Removed support for `activerecord-deprecated_finders` gem.
     ([commit](https://github.com/rails/rails/commit/78dab2a8569408658542e462a957ea5a35aa4679))
 
+*   Removed `ActiveRecord::ConnectionAdapters::Column::TRUE_VALUES` constant.
+    ([commit](https://github.com/rails/rails/commit/a502703c3d2151d4d3b421b29fefdac5ad05df61))
+
 ### Deprecations
 
 *   Deprecated passing a class as a value in a query. Users should pass strings