ruby on rails - How could I specify specific gem in Gemfile -

i want specify 2 gems in gemfile,

- activeadmin-dragonfly (0.0.2 89a47f9) - activeadmin-wysihtml5 (1.0.0 35d1a94) 

how ?

this idea

 gem 'activeadmin-dragonfly', github: 'stefanoverna/activeadmin-dragonfly' '~> 0.0.2 89a47f9' 

you can specify version of 1 gem github adding this:

gem 'gem_name', github: 'author/repository_name', ref: 'ref', tag: 'tag' 

in case:

gem 'activeadmin-dragonfly', github: 'stefanoverna/activeadmin-dragonfly', ref: '89a47f9' 

reference: http://bundler.io/v1.9/git.html