title: Failed to install gems via bundler Heroku, devise 4.5.0 not available
body: <p>I'm trying to push my rails app to heroku but it keeps failing, it specifies that devise 4.5.0 is not available, yet in my other apps it has that same version of devise and i have no problems deploying to heroku.</p>
  
  <pre><code>       Fetching gem metadata from https://rails-assets.org/...
  
         Fetching gem metadata from https://rubygems.org/............
  
         Fetching version metadata from https://rails-assets.org/..
  
         Fetching version metadata from https://rubygems.org/..
  
         Fetching dependency metadata from https://rails-assets.org/..
  
         Fetching dependency metadata from https://rubygems.org/.
  
         Fetching gem metadata from https://rails-assets.org/...
  
         Fetching version metadata from https://rails-assets.org/..
  
         Your bundle is locked to devise (4.5.0), but that version could not be found in
  
         any of the sources listed in your Gemfile. If you haven't changed sources, that
  
         means the author of devise (4.5.0) has removed it. You'll need to update your
  
         bundle to a different version of devise (4.5.0) that hasn't been removed in order to install.    
   !     Failed to install gems via Bundler.
   !     Push rejected, failed to compile Ruby app.  
   !     Push failed
  </code></pre>