Failing to build the website locally

[jgyasu]

I am trying to build the website locally, I have Ruby and Jekyll installed.

But when I run bundler install, I encounter the following error,

[!] There was an error parsing `Gemfile`: No such file or directory @ rb_sysopen - https://pages.github.com/versions.json. Bundler cannot continue.

 #  from /home/user/dir/openastronomy.github.io/Gemfile:5
 #  -------------------------------------------
 #  require 'open-uri'
 >  versions = JSON.parse(open('https://pages.github.com/versions.json').read)
 #  
 #  -------------------------------------------