RubyOnRails : To Solve error and install activeadmin for rails ver.5.0.0

I wrote ↓
http://blog.hhoshina.info/2016/07/rubyonrails-rails-500-release.html

To solve this error and install activeadmin i uses the fallowing gem configuration in gem-file and it works well::

_

gem 'devise'
gem 'activeadmin', github: 'activeadmin/activeadmin'
gem 'inherited_resources', github: 'activeadmin/inherited_resources'

Gemfile sample  ↓
https://github.com/hhoshina/rails5/blob/master/Gemfile