Gemfile

........................

gem 'geocoder'

#gem 'activeadmin'#, :github => 'gregbell/active_admin' bundle ругал на это и комментировал его
gem 'activeadmin'#, :github => 'gregbell/active_admin'
gem 'nokogiri'
gem 'fog' # добавил только это

gem 'wicked'

...................

gistfile1.txt

............
 config.serve_static_assets = true

  # Compress JavaScripts and CSS
  config.assets.compress = true

  # Don't fallback to assets pipeline if a precompiled asset is missed
  config.assets.compile = true

  config.assets.precompile += %w{active_admin.css active_admin/print.css active_admin.js redactor.css}
  # Generate digests for assets URLs
  config.assets.digest = true
  config.action_controller.asset_host = "http://stn-staging.s3.amazonaws.com" #путь к бакет

  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation can not be found)
  config.i18n.fallbacks = true

  # Send deprecation notices to registered listeners
  config.active_support.deprecation = :notify

  config.action_mailer.default_url_options = { :host => 'stn-staging.herokuapp.com' }

  config.action_mailer.delivery_method = :smtp
  config.action_mailer.smtp_settings = {
............

gistfile2.txt

# config/initializers/fog.rb
CarrierWave.configure do |config|
  if Rails.env.production?

    config.storage = :file

  elsif Rails.env.heroku_staging?

    config.fog_credentials = {
      :provider => 'AWS',
      :aws_access_key_id => 'AKIAIKID4I5C5W7NVF7A',
      :aws_secret_access_key => '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',
    }
    config.fog_directory = 'stn-staging'
    config.storage = :fog
  end

end