check rvm gem version in app template

gistfile1.rb

  say_wizard "switching to gemset '#{app_name}'"
  unless Gem.loaded_specs['rvm'].nil?
    if Gem.loaded_specs['rvm'].version > Gem::Version.create('1.11.3.4')
      raise "Please update rvm gem to 1.11.3.5 or newer"
    end
  end
  begin
    RVM.gemset_use! app_name
  rescue StandardError => e
    raise "rvm failure: unable to use gemset #{app_name}, reason: #{e}"
  end