title: upgrade ruby version without rvm
body: <p>I just did <code>apt-get install ruby.1.9.1</code>, installing it successfully. Now when I do <code>ruby -v</code>, it's still 1.8.7. Why won't it use the newly installed version? I don't know why, but I can't find anything via google on how to manage ruby versions without rvm. I know rvm is awesome, but in this case it has to be without rvm.</p>
  
  <p>Can anybody help me?</p>