Added a timezone by default
Added a timezone by default

All PHP date functions are triggering a warning if the timezone is not defined. The default config should allow having a working setup.
cachethq/cachet-buildpack,stof/heroku-buildpack-php,CHH/heroku-buildpack-php,CHH/heroku-buildpack-php,penciu/apache,penciu/apache,ryosuzuki/php-buildpack,AlphaStaxLLC/heroku-buildpack-php-custom,AlphaStaxLLC/heroku-buildpack-php-custom,jstacoder/heroku-buildpack-php-1,Scalingo/php-buildpack,stof/heroku-buildpack-php,pierredup/packager-buildpack-php,penciu/apache,pierredup/packager-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,CHH/heroku-buildpack-php,Scalingo/php-buildpack,Jonatasmz/php-buildpack,Scalingo/php-buildpack,mraymond/heroku-buildpack-php,nsg/dokku-buildpack-picocms,nsg/dokku-buildpack-picocms,ryosuzuki/php-buildpack,jstacoder/heroku-buildpack-php-1,Jonatasmz/php-buildpack,stof/heroku-buildpack-php,mraymond/heroku-buildpack-php