Add spring watch

When a pack moves, we want spring to update the loaded classes
so that packwerk prints correct results

lib/packs/rails/railtie.rb

@@ -11,7 +11,19 @@ class Railtie < ::Rails::Railtie
         # hook into packs-rails via ActiveSupport hooks.
         ActiveSupport.run_load_hooks(:packs_rails, Packs)
       end
-
+
+      config.after_initialize do |app|
+        if defined?(Spring)
+          puts "Hello Db Blasters!"
+          Packs::Specification::Configuration.fetch.pack_paths.each do |dir|
+            puts "#{dir}"
+            Dir["#{dir}/package.yml"].each { |f|
+              puts f
+              Spring.watch(f)
+            }
+          end
+        end
+      end
     end
   end
 end