Add support for IX dynos when autotuning
Add support for IX dynos when autotuning

CHH/heroku-buildpack-php,CHH/heroku-buildpack-php,stof/heroku-buildpack-php,penciu/apache,stof/heroku-buildpack-php,CHH/heroku-buildpack-php,penciu/apache,stof/heroku-buildpack-php,penciu/apache