Remove defunct saas/Gemfile and lockfile (#2566)

These are leftovers from when fizzy-saas was a standalone repository.
Since it was moved into fizzy as a path gem, the production bundle
uses Gemfile.saas at the root. Nothing references saas/Gemfile.

Also removes saas/bin/rails (references nonexistent test/dummy app)
and saas/bin/rubocop (references nonexistent saas/.rubocop.yml),
both equally defunct standalone-repo leftovers.

saas/bin/rails

@@ -1,14 +0,0 @@
-#!/usr/bin/env ruby
-# This command will automatically be run when you run "rails" with Rails gems
-# installed from the root of your application.
-
-ENGINE_ROOT = File.expand_path("..", __dir__)
-ENGINE_PATH = File.expand_path("../lib/fizzy/saas/engine", __dir__)
-APP_PATH = File.expand_path("../test/dummy/config/application", __dir__)
-
-# Set up gems listed in the Gemfile.
-ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
-require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
-
-require "rails/all"
-require "rails/engine/commands"

saas/bin/rubocop

@@ -1,8 +0,0 @@
-#!/usr/bin/env ruby
-require "rubygems"
-require "bundler/setup"
-
-# explicit rubocop config increases performance slightly while avoiding config confusion.
-ARGV.unshift("--config", File.expand_path("../.rubocop.yml", __dir__))
-
-load Gem.bin_path("rubocop", "rubocop")