title: rails 5.0.7 Multiple default gems and unable to uninstall any default gem
body: <p>I had bundler 1.16 installed and rails was complaining that my bundle had previously been created with a higher version of bundler So I installed bundler 2.0.1 with the --default switch but that still left a default 1.16.6 as well I'm trying to uninstall 1.16.6 but I get error can't uninstall a default gem How can I remove it's default flag then? Also if I'm using rails 5.0.7 which ruby version should I use?</p>