more selective exporting of env vars
more selective exporting of env vars

a2service/heroku-buildpack-php,a2service/heroku-buildpack-php,flant/heroku-buildpack-php,flant/heroku-buildpack-php,thecsea/heroku-buildpack-php-with-ioncube,rikur/heroku-buildpack-php,heroku/heroku-buildpack-php,heroku/heroku-buildpack-php,puteulanus/heroku-buildpack-php,rikur/heroku-buildpack-php,jayelkaake/heroku-buildpack-magento,rikur/heroku-buildpack-php,emeth-/heroku-buildpack-php,heroku/heroku-buildpack-php,a2service/heroku-buildpack-php,flant/heroku-buildpack-php,alzheic/heroku-buildpack-aop,emeth-/heroku-buildpack-php,puteulanus/heroku-buildpack-php,alzheic/heroku-buildpack-aop,rikur/heroku-buildpack-php,jayelkaake/heroku-buildpack-magento,emeth-/heroku-buildpack-php,createmultimedia/heroku-buildpack-php,heroku/heroku-buildpack-php,dzuelke/heroku-buildpack-php,dzuelke/heroku-buildpack-php,createmultimedia/heroku-buildpack-php,thecsea/heroku-buildpack-php-with-ioncube,createmultimedia/heroku-buildpack-php,dzuelke/heroku-buildpack-php,jayelkaake/heroku-buildpack-magento,puteulanus/heroku-buildpack-php,emeth-/heroku-buildpack-php,alzheic/heroku-buildpack-aop,thecsea/heroku-buildpack-php-with-ioncube