ruby >= 2.3 ? rubygems 3 && bundler 2 : rubygems 2 && bundler 1
ruby >= 2.3 ? rubygems 3 && bundler 2 : rubygems 2 && bundler 1

because bundler 2 requires rubygems 3, and ruby < 2.3 doesn't support rubygems 3

asakusarb/action_args