Amazon-ecs - trying to access outdated Ruby on Rails project

I'm trying to learn how to use the gem, Amazon-ecs, with Ruby on Rails and found a project that is a bit outdated.
Link:http://ift.tt/1LV3Mnp

When I run 'rails s', I get this error
Link: http://ift.tt/1QO7BKq

This error is probably because I have to fill in the keys, but I am not sure how to do it.

Amazon::Ecs.options = {
  :associate_tag => '[Your Associate Tag]',
  :AWS_access_key_id => '[Your Access Key ID]',       
  :AWS_secret_key => '[Your Secret Key]'
}

How can I run this application on localhost? And how can I get started in an empty Ruby on Rails project?

Thanks