module Middleman

def setup_bundler

Set BUNDLE_GEMFILE and run Bundler setup. Raises an exception if there is no Gemfile 
def setup_bundler
  if found_gemfile_root = findup('Gemfile', ENV['MM_ROOT'])
    ENV['BUNDLE_GEMFILE'] ||= File.join(found_gemfile_root, 'Gemfile')
  end
  unless File.exist?(ENV['BUNDLE_GEMFILE'])
    ENV['BUNDLE_GEMFILE'] = File.expand_path('../../../../Gemfile', __FILE__)
  end
  if File.exist?(ENV['BUNDLE_GEMFILE'])
    require 'bundler/setup'
    Bundler.require
  else
    raise "Couldn't find your Gemfile. Middleman projects require a Gemfile for specifying dependencies."
  end
end