我是Rails的新人，我读了 Ruby on Rails Tutorial 并制作了一个sample_app。我今天才使用Cloud9。但我想在我的Mac上运行这个应用程序。所以我将所有文件推送到Bitbucket并在我的Mac中克隆这个repo。
然后，我运行bundle install和rails db:migrate，并且不会出现任何错误。此外，rails test通过。
当我运行rails s时，我得到了这个输出：
> Booting Puma
=> Rails 5.0.0 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
DEPRECATION WARNING: Sprockets method `register_engine` is deprecated.
Please register a mime type using `register_mime_type` then
use `register_compressor` or `register_transformer`.
https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors
(called from block (2 levels) in <class:Railtie> at /Users/Shu/.rvm/gems/ruby-2.3.0/gems/sass-rails-5.0.5/lib/sass/rails/railtie.rb:57)
DEPRECATION WARNING: Sprockets method `register_engine` is deprecated.
Please register a mime type using `register_mime_type` then
use `register_compressor` or `register_transformer`.
https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors
(called from block (2 levels) in <class:Railtie> at /Users/Shu/.rvm/gems/ruby-2.3.0/gems/sass-rails-5.0.5/lib/sass/rails/railtie.rb:58)
Puma starting in single mode...
* Version 3.4.0 (ruby 2.3.0-p0), codename: Owl Bowl Brawl
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://localhost:3000
Use Ctrl-C to stop
但是当我打开http://localhost:3000时，它是空白的，服务器没有任何变化。这些警告也存在于Cloud9中，但Cloud9可以打开此站点。
我尝试rails new一个新的应用程序，它运作成功。我该怎么办？