How do I enable PHP error logging on Amazon Elastic Beanstalk?

I would like to view PHP errors in the Amazon Elastic Beanstalk logs. By default, this does not appear to be on.

I attempted using an ebextensions.config file according the answer here (http://ift.tt/1P3i1H2) but that hasn't added any PHP error logging to my application?

Anybody know how to do this?