我按照这里的说明进行操作：https://help.github.com/articles/setting-up-your-github-pages-site-locally-with-jekyll/在Ubuntu 14.04上用Guthub设置Jekyll，我得到的输出是'm running into a problem when I try to run 614557 . Here'：
Fetching gem metadata from https://rubygems.org/
Fetching version metadata from https://rubygems.org/
Fetching dependency metadata from https://rubygems.org/
Rubygems 1.8.23 is not threadsafe, so your gems will be installed one at a time. Upgrade to Rubygems 2.1.0 or higher to enable parallel gem installation.
Your user account isn't allowed to install to the system Rubygems.
You can cancel this installation and run:
bundle install --path vendor/bundle
to install the gems into ./vendor/bundle/, or you can enter your password
and install the bundled gems to Rubygems using sudo.
Password:
Installing RedCloth 4.2.9 with native extensions
Using i18n 0.7.0
Using json 1.8.3
Installing minitest 5.8.3
Using thread_safe 0.3.5
Using addressable 2.4.0
Installing blankslate 2.1.2.4
Installing fast-stemmer 1.0.2 with native extensions
Using coffee-script-source 1.10.0
Using execjs 2.7.0
Using colorator 0.1
Using ffi 1.9.10
Using multipart-post 2.0.0
Using gemoji 2.1.0
Using net-dns 0.8.0
Installing public_suffix 1.5.3
Gem::InstallError: public_suffix requires Ruby version >= 2.0.
Using jekyll-paginate 1.1.0
Using sass 3.4.22
Using rb-fsevent 0.9.7
Installing kramdown 1.5.0
Installing liquid 2.6.1
Using mercenary 0.3.6
Installing posix-spawn 0.3.11 with native extensions
Installing yajl-ruby 1.2.1 with native extensions
Installing redcarpet 3.1.2 with native extensions
Using safe_yaml 1.0.4
Using mini_portile2 2.1.0
Using pkg-config 1.1.7
Installing jekyll-sitemap 0.6.3
Installing maruku 0.7.0
Installing rdiscount 2.1.7 with native extensions
Using terminal-table 1.6.0
Using bundler 1.12.5
Using tzinfo 1.2.2
Installing parslet 1.5.0
Installing classifier-reborn 2.0.4
Using coffee-script 2.4.1
Using ethon 0.9.0
Using rb-inotify 0.9.7
Using faraday 0.9.2
An error occurred while installing public_suffix (1.5.3), and Bundler cannot continue.
Make sure that `gem install public_suffix -v '1.5.3'` succeeds before bundling.
当我运行“sudo gem install public_suffix -v'1.5.3'”时，我得到：
Successfully installed public_suffix-1.5.3
Parsing documentation for public_suffix-1.5.3
Done installing documentation for public_suffix after 0 seconds
1 gem installed
当我运行“ruby --version”时，我得到：
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]
知道下一步该尝试什么吗？