group :production do
  gem 'pg'
  gem 'rails_12factor'
end

从错误中可以清楚地看出,宝石pg需要添加到你的Gemfile中.您可能只是添加了它,但您需要为开发和生产机器添加gem,因为Heroku应用程序是您系统的生产机器,而您的localhost是开发.

您的Gemfile应如下所示：

source 'https://rubygems.org'
ruby '2.0.0'


gem 'rails','4.0.0'
gem 'bootstrap-sass','2.3.2.0'
gem 'bcrypt-ruby','3.0.0'
gem 'faker','1.1.2'
gem 'will_paginate','3.0.4'
gem 'bootstrap-will_paginate','0.0.9'

group :development,:test do
  gem 'sqlite3','1.3.8'
  gem 'rspec-rails','2.13.1'

end
group :doc do
  gem 'sdoc','0.3.20',require: false
end

group :production do
  gem 'pg','0.15.1'
  gem 'rails_12factor'
end