fix apt-transport-https checking (#520)
fix apt-transport-https checking (#520)

* fix apt-transport-https checking

* only uninstall if installed

* fix logic

* clear out old sources

heroku/heroku-cli,heroku/heroku-cli,heroku/cli,heroku/cli,heroku/cli,heroku/heroku-cli,heroku/heroku-cli,heroku/cli