我们如何在heroku上安装FFMPEG for Ruby app？

I am trying to install FFMPEG for a Ruby app(Web framework- Sinatra) on Heroku. I have tried heroku-buildpack-multi (github.com/ddollar/heroku-buildpack-multi.git) plugin, but seems it's stopped working from Jan 01,2017 as it threw error with same message. I followed steps from this link I am trying to install FFMPEG for a Ruby app(We