Upload task for Capistrano 3

upload.rake

namespace :deploy do
  desc "Uploads a comma-separated list of files from ENV['files']"
  task :upload do
    on roles(:app) do
      ENV.fetch('files', ENV['FILES']).split(',').map(&:strip).each do |file|
        upload! file, current_path.join(file), recursive: true
      end
    end
  end
end