title: Could not find devise-1.4.6 in any of the sources
body: <p>I have installed devise 1.4.6 succesfully on my local development environment. I have this in my bundle file: gem 'devise'</p>
  
  <p>But when I want to deploy it to heroku, it says "Could not find devise-1.4.6 in any of the sources". What should I do? Thanks!</p>