*   Update example of passing a proc to `:message` option for validating records.

    This behavior was recently changed in [Pull Request #24199](https://github.com/rails/rails/pull/24119) to
    pass the object being validated as first argument to the `:message` proc,
    instead of the key of the field being validated.
    
    *Prathamesh Sonpatki*

*   Added new guide: Action Cable Overview.   

    *David Kuhta*

 
## Rails 5.0.0.beta3 (February 24, 2016) ##

*   No changes.


## Rails 5.0.0.beta2 (February 01, 2016) ##

*   No changes.


## Rails 5.0.0.beta1 (December 18, 2015) ##

*   Add code of conduct to contributing guide.

    *Jon Moss*

*   New section in Configuring: Configuring Active Job.

    *Eliot Sykes*

*   New section in Active Record Association Basics: Single Table Inheritance.

    *Andrey Nering*

*   New section in Active Record Querying: Understanding The Method Chaining.

    *Andrey Nering*

*   New section in Configuring: Search Engines Indexing.

    *Andrey Nering*

Please check [4-2-stable](https://github.com/rails/rails/blob/4-2-stable/guides/CHANGELOG.md) for previous changes.