Heroku、CarrierWaveとAWSを画像投稿機能をつけたいが、[fog]がうまく機能しない

現在、漫画家の友人のポートフォリページをrailsを利用して作成しています。
イラストを投稿できるようにするため、CarrierWaveとAWSを利用しようとしてます。
しかし一通り入力、設定が完了したので、herokuにpush しようとするとターミナルに下記の表示が出てき、
最終的にpushをrejectされてしまいます。
fogに関するものが全て読み込めてないようです。

現在の環境、状況として
・mac OS 10.13.6
・ruby2.6.5
・rails 5.2.4.2
・gem fog　インストール済み
・AWS、S3アカウント作成済み
・Herokuアカウント作成済み
⇨一度デプロイ済み、投稿機能を追加するために再度プッシュしたのちリジェクトされる
・環境変数（アクセスキー等）も設定済み

発生している問題・エラーメッセージ

エラーメッセージ
remote:        [fog][DEPRECATION] Unable to load Fog::Atmos::Storage
remote:        [fog][DEPRECATION] Falling back to deprecated constant Fog::Storage::Atmos. The preferred format of service provider constants has changed from service::provider to provider::service. Please update this service provider to use the preferred format.
remote:        [fog][DEPRECATION] Unable to load Fog::Clodo::Compute
remote:        [fog][DEPRECATION] Falling back to deprecated constant Fog::Compute::Clodo. The preferred format of service provider constants has changed from service::provider to provider::service. Please update this service provider to use the preferred format.
remote:        [fog][DEPRECATION] Unable to load Fog::DigitalOcean::Compute
remote:        [fog][DEPRECATION] Falling back to deprecated constant Fog::Compute::DigitalOcean. The preferred format of service provider constants has changed from service::provider to provider::service. Please update this service provider to use the preferred format.
remote:        [fog][DEPRECATION] Unable to load Fog::Dnsimple::DNS
remote:        [fog][DEPRECATION] Falling back to deprecated constant Fog::DNS::Dnsimple. The preferred format of service provider constants has changed from service::provider to provider::service. Please update this service provider to use the preferred format.
・
・　一部省略
・
remote:        [fog][DEPRECATION] Unable to load Fog::Aliyun::Compute
remote:        [fog][DEPRECATION] Falling back to deprecated constant Fog::Compute::Aliyun. The preferred format of service provider constants has changed from service::provider to provider::service. Please update this service provider to use the preferred format.
remote:        [fog][DEPRECATION] Unable to load Fog::Aliyun::Storage
remote:        [fog][DEPRECATION] Falling back to deprecated constant Fog::Storage::Aliyun. The preferred format of service provider constants has changed from service::provider to provider::service. Please update this service provider to use the preferred format.
remote:        rake aborted!
remote:        NoMethodError: undefined method `~' for :smtp:Symbol
remote:        /tmp/build_5342ac7d37b0f1a4dbd2dd2e806a20bc/config/environments/production.rb:66:in `block (2 levels) in <main>'
・
・一部省略
・
・
/tmp/build_5342ac7d37b0f1a4dbd2dd2e806a20bc/vendor/bundle/ruby/2.6.0/gems/railties-5.2.4.2/lib/rails/application.rb:520:in `block in run_tasks_blocks'
remote:        /tmp/build_5342ac7d37b0f1a4dbd2dd2e806a20bc/vendor/bundle/ruby/2.6.0/gems/sprockets-rails-3.2.1/lib/sprockets/rails/task.rb:62:in `block (2 levels) in define'
remote:        /tmp/build_5342ac7d37b0f1a4dbd2dd2e806a20bc/vendor/bundle/ruby/2.6.0/gems/rake-13.0.1/exe/rake:27:in `<top (required)>'
remote:        Tasks: TOP => environment
remote:        (See full trace by running task with --trace)
remote: 
remote:  !
remote:  !     Precompiling assets failed.
remote:  !
remote:  !     Push rejected, failed to compile Ruby app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...
remote: 
remote: !	Push rejected to ●●●●●.
remote: 
To https://git.heroku.com/●●●●●.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/●●●●●git'

該当のソースコード

ソースコード
carrierwave.rb
unless Rails.env.development? || Rails.env.test?
  CarrierWave.configure do |config|
     config.fog_provider = 'fog/●●●●●'
     config.fog_directory = ENV['mc']
    config.fog_credentials = {
      provider: 'AWS',
      aws_access_key_id: 'A●●●●●G',
      aws_secret_access_key: 'xU●●●●●X',
      region: 'ap-northeast-1'
    }
    config.cache_storage = :fog
    config.fog_public = false
  end
end

uploader/image_uploader.rb
class ImageUploader < CarrierWave::Uploader::Base

  if Rails.env.development?
  storage :file
 
  elsif Rails.env.test?
  storage :file

  else
  storage :fog
  end

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end