title: Ruby on Rails: skip adding mini_racer to the bottom of the gemfile?
body: <p>My <code>rails generate react_on_rails:install</code> is adding the <code>mini_racer</code> gem to the bottom of my gemfile. I don't want rails to do this because I already have <code>mini_racer</code> added to my gemfile.</p>
  <p>Is there a global way to disable this functionality, or a flag I can pass in to the rails cli?</p>
  <p>I am using Rails 6.</p>