SugarCRM on Bluemix

I'm trying to deploy SugarCRM community version on Bluemix. I'm using PHP runtime, I forked out the project from the git repository of SugarCRM community and I bound a mySQL service to the application.

The application runs and came out with the standard installation page of sugarcrm, as I proceed, the screen shows me this error:

Functions associated with the Multibyte Strings PHP extension (mbstring) that are needed by the Sugar application were not found.

MB String Module

Generally, the mbstring module is not enabled by default in PHP and must be activated with --enable-mbstring when the PHP binary is built. Please refer to your PHP Manual for more information on how to enable mbstring support. Location of your PHP configuration file (php.ini): /home/vcap/app/vendor/heroku/heroku-buildpack-php/conf/php/php.ini

I looked through the installation guide of SugarCRM, it seems like I have to go to the root directory of the server to modify php.ini. But I can't find any way to do that since Bluemix is a PaaS.. Anyone can help me with this?