Improved PHP extension installs

Change effective on 26 November 2014

In addition to extensions listed in the require section of your project’s composer.json, any PHP extension required by a dependency of a project pushed to Heroku will now also be installed automatically.

For example, if a project depends on the stripe/stripe-php PHP SDK for Stripe, the mbstring extension required by the Stripe SDK will now be installed upon deploy, without the ext-mbstring package listed in the require section of your project’s composer.json.