- Branch
  - Figure out version numbers and install new ruby version and rails gem (new gemset for RVM, not for rbenv/chruby), change local ruby version
  - Remove Gemfile.lock and strip version numbers from Gemfile apart from ruby and rails (can be repopulated from versions installed when creating a blank test app; grab this new Gemfile)



====== 4 -> 6 ======

===== development/testing =====


''rails webpacker:install''

''bin/rails db:environment:set RAILS_ENV=test''

Create `app/assets/config/manifest.js` and include directories in `app/assets` that need to be searched (may not need `fonts`, for instance):

    //= link_tree ../images
    //= link_tree ../fonts
    //= link_directory ../javascripts .js
    //= link_directory ../stylesheets .css

===== production =====

Upgrade node.js