title: Upgrading Rails application with Git
body: <p>Good day,</p>
  
  <p>I would like to upgrade my rails 2.3 application to rails 3. I would like to know what is the proper or right way to use git to manage the upgrading and continue it on each release of my application.</p>
  
  <p>I've been using git for only pull and push but not on a bigger scale. </p>
  
  <p>How can I achieve this?</p>