make sure generate_packs runs

Author: Judahmeek

rakelib/shakapacker_examples.rake

@@ -42,6 +42,7 @@ namespace :shakapacker_examples do # rubocop:disable Metrics/BlockLength
       end
       sh_in_dir(example_type.dir, generator_commands)
       sh_in_dir(example_type.dir, "npm install")
+      sh_in_dir(example_type.dir, "bin/rake react_on_rails:generate_packs")
     end
   end