Build something that works
Simple to deploy to Digital Ocean. I've done it with ETsyDEMo. :) You just have to follow the instructions laid down by the Digital Ocean team on how to deploy a rails app.
You can certainly deploy your Rails app on Digital Ocean, but I highly recommend using Heroku instead. Not only does Digital Ocean not have a free tier, but it requires more development experience to use. Plus, Heroku is optimized specifically for Rails apps (though it's now able to support other languages/frameworks as well). Here is a good article with the pros and cons of each: https://www.airpair.com/ruby-on-rails/posts/rails-host-comparison-aws-digitalocean-heroku-engineyard.
Is there a specific reason why you are interested in using Digital Ocean instead?