title: Console prints not appearing when using Docker in Ruby on Rails
body: <p>I've been trying to use Docker for development, it works pretty well but one of the things that annoys me is not being able to see the console prints.</p>
  
  <p>Rails server (exactly the same application):</p>
  
  <pre><code>Started GET "/" for ::1 at 2015-10-14 22:18:28 +0200
  Processing by PagesController#home as HTML
  foobar
  Rendered pages/home.html.erb within layouts/home (0.0ms)
  Completed 200 OK in 20ms (Views: 19.7ms | ActiveRecord: 0.0ms)
  </code></pre>
  
  <p>Docker: </p>
  
  <pre><code>Started GET "/" for 192.168.99.1 at 2015-10-14 20:18:44 +0000
  Processing by PagesController#home as HTML
  Rendered pages/home.html.erb within layouts/home (0.1ms)
  Completed 200 OK in 179ms (Views: 177.6ms | ActiveRecord: 0.0ms)
  </code></pre>
  
  <p>These logs are from tailing the log/development.log file within my container.</p>
  
  <p>Has anyone else encountered this before? How to solve this? Cheers!</p>