def index
      validate_arguments!

      stacks_data = api.get_stack(app).body

      styled_header("#{app} Available Stacks")
      stacks = stacks_data.map do |stack|
        row = [stack['current'] ? '*' : ' ', Codex.out(stack['name'])]
        row << '(beta)' if stack['beta']
        row << '(deprecated)' if stack['deprecated']
        row << '(prepared, will migrate on next git push)' if stack['requested']
        row.join(' ')
      end
      styled_array(stacks)
    end
def index
      validate_arguments!

      stacks_data = api.get_stack(app).body

      styled_header("#{app} Available Stacks")
      stacks = stacks_data.map do |stack|
        row = [stack['current'] ? '*' : ' ', Codex.out(stack['name'])]
        row << '(beta)' if stack['beta']
        row << '(deprecated)' if stack['deprecated']
        row << '(prepared, will migrate on next git push)' if stack['requested']
        row.join(' ')
      end
      styled_array(stacks)
    end
stack

 show the list of available stacks

Example:

 $ heroku stack
 === example Available Stacks
   cedar-10
 * cedar-14