I’m : a web and mobile developer based in the Manning Valley, Australia.

Bootstrap 3.3 with Ruby on Rails 4.2

If you're wanting to get Bootstrap 3.3.6 installed alongside a Rails 4.2.5 app then has the solution.

And while you're at it has the details on how to nicely integrate flash messages using Bootstrap styling. One of the comments suggests changing flash_type to flash_type.to_sym