According to these release notes, Ruby versions prior to 2.1.x
has been end-of-lifed.
Additionally, this codebase makes use of (required) keyword arguments.
From ember-cli-rails@0.4.0 and on, we will no longer support versions of Ruby
prior to 2.1.0.
ember-cli-rails@0.8.0 adds support for Rails 5, which depends on rack@2.0.x,
which requires Ruby 2.2.2 or greater.
From ember-cli-rails@0.8.0 and on, we will no longer support versions of Ruby
prior to 2.2.2.
To use ember-cli-rails with older versions of Ruby, try the 0.3.x series.
According to the Rails Maintenance Policy, Rails versions
prior to 3.2.x have been end-of-lifed. Additionally, the 4.0.x series no
longer receives bug fixes of any sort.
From ember-cli-rails@0.4.0 and on, we will no longer support versions of Rails
prior to 3.2.0, nor will we support the 4.0.x series of releases.
To use ember-cli-rails with older versions of Rails, try the 0.3.x series.