Appending migrations to migration path(s) does not work in Rails 5.1

[jayroh]

What I just ran into:

1. Upgraded app to rails 5.1
2. ran rake db:drop db:create db:migrate db:test:prepare
3. ran rake spec

Result:

Payola tables were not created.

Fix:

initializer :append_migrations do |app|
  unless app.root.to_s.match root.to_s
    config.paths["db/migrate"].expanded.each do |expanded_path|
      app.config.paths["db/migrate"] << expanded_path

      # ADD THE FOLLOWING
      ActiveRecord::Migrator.migrations_paths << expanded_path
    end
  end
end

After changing that locally, everything looks to be back in working shape