Update changelog for v0.3.1
Update changelog for v0.3.1

stof/heroku-buildpack-php,Jonatasmz/php-buildpack,Scalingo/php-buildpack,ryosuzuki/php-buildpack,penciu/apache,stof/heroku-buildpack-php,nsg/dokku-buildpack-picocms,OKAMca/heroku-buildpack-php,OKAMca/heroku-buildpack-php,penciu/apache,Jonatasmz/php-buildpack,CHH/heroku-buildpack-php,ryosuzuki/php-buildpack,OKAMca/heroku-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,CHH/heroku-buildpack-php,bobmaerten/dokku-buildpack-php,mraymond/heroku-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,Scalingo/php-buildpack,pierredup/packager-buildpack-php,Scalingo/php-buildpack,CHH/heroku-buildpack-php,mraymond/heroku-buildpack-php,cachethq/cachet-buildpack,penciu/apache,jstacoder/heroku-buildpack-php-1,pierredup/packager-buildpack-php,stof/heroku-buildpack-php,nsg/dokku-buildpack-picocms,bobmaerten/dokku-buildpack-php,AlphaStaxLLC/heroku-buildpack-php-custom,jstacoder/heroku-buildpack-php-1