PHP extensions update and Argon2 support

Change effective on 10 July 2018

The following PHP extensions have been added or updated:

  • ext-apcu, version 5.1.12
  • ext-blackfire, version 1.22.0
  • ext-mongodb, version 1.5.1

PHP 7.2 on the heroku-18 stack now supports the Argon2 password hashing algorithm.

All versions of PHP 7 on all stacks are now built with --enable-opcache-file.