Use with_original_env to fix Bundler binstub error

Author: mattbrictson

Rakefile

@@ -93,7 +93,7 @@ def in_example_app(*command_opts)
     app_dir = opts.fetch(:app_dir, app_dir)
   end
   Dir.chdir(app_dir) do
-    Bundler.with_clean_env do
+    Bundler.with_original_env do
       sh *command_opts unless command_opts.empty?
       yield if block_given?
     end