git push heroku masterができない

Question

herokuにアプリを上げたいのですが、その際git push heroku masterを実行しますがエラーが
出てしまいます。 NameError: uninitialized constant Deviseとエラーが出るのですが、
gem deviseを使っている影響で上記のエラーが出てしまうのでしょうか？

gemfileの一覧です

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.2.1'
# Use mysql as the database for Active Record
gem 'mysql2','~> 0.3.20'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.1.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc

# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Unicorn as the app server
# gem 'unicorn'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug'

  # Access an IRB console on exception pages or by using <%= console %> in views
  gem 'web-console', '~> 2.0'

  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem "devise"
gem "better_errors"
gem "binding_of_caller"
gem 'pry-rails'
gem 'pry-doc'
gem 'pry-byebug'
gem 'pry-stack_explorer'
gem 'devise-i18n'
gem 'rails-i18n'
gem 'devise-i18n-views'
gem 'carrierwave'
gem 'rmagick'
gem 'bootstrap-sass'
group :production, :staging do
  gem 'rails_12factor'
end
group :development, :production, :test do
  end
end

Answer 1

deviseがproduction環境で読むように書かれていないようです。
インデントなどをしっかりして、どれをdevelopmentで読み込み、どれは全体で使うのかを整理してみてください。

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug'

  # Access an IRB console on exception pages or by using <%= console %> in views
  gem 'web-console', '~> 2.0'

  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem "devise"
gem "better_errors"
gem "binding_of_caller"
gem 'pry-rails'
gem 'pry-doc'
gem 'pry-byebug'
gem 'pry-stack_explorer'
gem 'devise-i18n'
gem 'rails-i18n'
gem 'devise-i18n-views'
gem 'carrierwave'
gem 'rmagick'
gem 'bootstrap-sass'
group :production, :staging do
  gem 'rails_12factor'
end
group :development, :production, :test do
  end
end