由于现在跟着 Ruby on Rails 4 Tutorial 自学，用的版本是 ruby2.0.现在无法部署到 heroku 上，以下是提示错误信息： An error occurred while installing ruby-2.0.0-p648 Heroku recommends you use the latest supported Ruby version listed here:

我查了一下官网，以下是 heroku 的官网介绍： The tutorial assumes that you have: a free Heroku account. Ruby 2.3.4 installed locally - see the installation guides for Ruby and Rails on OS X, Windows, and Linux. Bundler installed locally - run gem install bundler.