title: Terminal doesn't end process after using rails g model command
body: <p>I recently find sometimes when I use rails command in terminal, it won't end the process itself:</p>
  
  <pre><code>blog (master) $ rails g model Article title:string text:text
  Running via Spring preloader in process 33892
        invoke  active_record
        create    db/migrate/20161029085205_create_articles.rb
        create    app/models/article.rb
        invoke    test_unit
        create      test/models/article_test.rb
        create      test/fixtures/articles.yml
  </code></pre>
  
  <p>and I have to manually close it with <kbd>cmd</kbd> + <kbd>c</kbd>:</p>
  
  <pre><code>blog (master) $ rails g model Article title:string text:text
  Running via Spring preloader in process 33892
        invoke  active_record
        create    db/migrate/20161029085205_create_articles.rb
        create    app/models/article.rb
        invoke    test_unit
        create      test/models/article_test.rb
        create      test/fixtures/articles.yml
  ^Cblog (master) $
  </code></pre>
  
  <p>It was fine before I updated MacOS to Sierra, but I'm not sure if that's the cause.</p>
  
  <p>I followed all the step from <a href="http://railsapps.github.io/installrubyonrails-mac.html" rel="nofollow">http://railsapps.github.io/</a> to install rvm, rails, etc. All I did additionally was to change my bash_profile to this:</p>
  
  <pre><code>export PATH="/usr/local/sbin:$PATH"
  export PATH="$PATH:$HOME/.rvm/bin"
  source /Users/xiaohuli/.rvm/scripts/rvm
  </code></pre>
  
  <p>Does anyone have the same problem like mine? Why this is happening?</p>