我对Ruby很陌生。我是按照TeamTreehouse上的说明在OSX（约塞米蒂）上安装Ruby开发环境的。
当我到了创建测试应用程序的步骤时。最后失败了。拒绝许可。：（不知道我做错了什么，我确实试过运行gem install debug inspector和bundle exec spring binstubb，但它们都失败了。

[]rails new testapp
      create  
      create  README.rdoc
      create  Rakefile
      create  config.ru
      create  .gitignore
      create  Gemfile
      create  app
      create  app/assets/javascripts/application.js
      create  app/assets/stylesheets/application.css
      create  app/controllers/application_controller.rb
      create  app/helpers/application_helper.rb
      create  app/views/layouts/application.html.erb
      create  app/assets/images/.keep
      create  app/mailers/.keep
      create  app/models/.keep
      create  app/controllers/concerns/.keep
      create  app/models/concerns/.keep
      create  bin
      create  bin/bundle
      create  bin/rails
      create  bin/rake
      create  bin/setup
      create  config
      create  config/routes.rb
      create  config/application.rb
      create  config/environment.rb
      create  config/secrets.yml
      create  config/environments
      create  config/environments/development.rb
      create  config/environments/production.rb
      create  config/environments/test.rb
      create  config/initializers
      create  config/initializers/assets.rb
      create  config/initializers/backtrace_silencers.rb
      create  config/initializers/cookies_serializer.rb
      create  config/initializers/filter_parameter_logging.rb
      create  config/initializers/inflections.rb
      create  config/initializers/mime_types.rb
      create  config/initializers/session_store.rb
      create  config/initializers/wrap_parameters.rb
      create  config/locales
      create  config/locales/en.yml
      create  config/boot.rb
      create  config/database.yml
      create  db
      create  db/seeds.rb
      create  lib
      create  lib/tasks
      create  lib/tasks/.keep
      create  lib/assets
      create  lib/assets/.keep
      create  log
      create  log/.keep
      create  public
      create  public/404.html
      create  public/422.html
      create  public/500.html
      create  public/favicon.ico
      create  public/robots.txt
      create  test/fixtures
      create  test/fixtures/.keep
      create  test/controllers
      create  test/controllers/.keep
      create  test/mailers
      create  test/mailers/.keep
      create  test/models
      create  test/models/.keep
      create  test/helpers
      create  test/helpers/.keep
      create  test/integration
      create  test/integration/.keep
      create  test/test_helper.rb
      create  tmp/cache
      create  tmp/cache/assets
      create  vendor/assets/javascripts
      create  vendor/assets/javascripts/.keep
      create  vendor/assets/stylesheets
      create  vendor/assets/stylesheets/.keep
         run  bundle install
Fetching gem metadata from https://rubygems.org/............
Fetching version metadata from https://rubygems.org/...
Fetching dependency metadata from https://rubygems.org/..
Resolving dependencies...
Using rake 10.4.2
Using i18n 0.7.0
Using json 1.8.2
Installing minitest 5.6.1
Using thread_safe 0.3.5
Using tzinfo 1.2.2
Using activesupport 4.2.1
Using builder 3.2.2
Using erubis 2.7.0
Using mini_portile 0.6.2
Using nokogiri 1.6.6.2
Using rails-deprecated_sanitizer 1.0.3
Using rails-dom-testing 1.0.6
Using loofah 2.0.2
Using rails-html-sanitizer 1.0.2
Using actionview 4.2.1
Using rack 1.6.1
Using rack-test 0.6.3
Using actionpack 4.2.1
Using globalid 0.3.5
Using activejob 4.2.1
Using mime-types 2.5
Using mail 2.6.3
Using actionmailer 4.2.1
Using activemodel 4.2.1
Using arel 6.0.0
Using activerecord 4.2.1

Errno::EACCES: Permission denied @ dir_s_mkdir - /Users/jeremy/.rbenv/versions/2.2.1/lib/ruby/gems/2.2.0/extensions/x86_64-darwin-14/2.2.0-static/debug_inspector-0.0.2
An error occurred while installing debug_inspector (0.0.2), and Bundler cannot continue.
Make sure that `gem install debug_inspector -v '0.0.2'` succeeds before bundling.
         run  bundle exec spring binstub --all
rbenv: spring: command not found

The `spring' command exists in these Ruby versions:
  2.2.2