Gemfile
source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }
gemspec
version = ENV["RAILS_VERSION"] || "4.2"
rails = case version
when "master"
{github: "rails/rails"}
else
"~> #{version}.0"
end
gem "rails", rails
group :test do
gem "simplecov", require: false
gem "simplecov-console", require: false
end