Spree bootstrap frontend doesn't work on rails 5

[Adam Marsh]

Are there better instructions that here: https://github.com/Purepoint/spree_bootstrap_frontend on getting this to work on rails 5? Followed the install instructions to the letter and it's throwing rails 5 errors.
Bundler could not find compatible versions for gem "sass-rails":
  In snapshot (Gemfile.lock):
    sass-rails (= 5.0.6)

  In Gemfile:
    sass-rails (~> 5.0)

    spree_bootstrap_frontend was resolved to 2.4.0.rc3, which depends on
      spree_bootstrap was resolved to 2.4.0.rc3, which depends on
        sass-rails (~> 4.0)