rmagick on Heroku with Bundler

I am getting this error:

/app/che.rb:6:in `require': no such file to load -- rmagick (LoadError)
from /app/che.rb:6:in `<top (required)>'

It's 开发者_开发技巧a sintra app: https://github.com/rtacconi/cheguevarafx/blob/master/che.rb The Gemfile: https://github.com/rtacconi/cheguevarafx/blob/master/Gemfile All files of the app: https://github.com/rtacconi/cheguevarafx

I tried many ways without success. It seems that during the deployment is installed, but it is not.

Please advise.

use the following Gemfile

source "http://rubygems.org"

gem 'rack'
gem 'sinatra'
gem "rmagick", "2.12.2", :require => "RMagick"

and include rmagick with:

require 'RMagick'