guardfile modifications to play nice with zeus on vagrant

Guardfile

# A sample Guardfile
# More info at https://github.com/guard/guard#readme
if Dir.pwd == '/vagrant'
  Guard::UI.info 'detected vagrant, enabling force polling'
  Guard.options[:force_polling] = true
  Guard.listener.options[:force_polling] = true
end

guard 'rspec', cmd: 'zeus rspec', all_on_start: false, all_after_pass: false do
  #...
  if Guard::options.force_polling
    Guard::UI.info "detected forced_polling: will touch test file to ensure zeus restarts"
    callback(:run_on_modifications_begin) do |a, b, files|
      files.each do |file|
        ['app', '.'].each do |prefix|
          test_target = file.gsub(/spec\/(.+)_spec.rb/, "#{prefix}/\\1.rb")
          if File.exists? test_target
            Guard::UI.info "touching #{test_target} (for zeus reload)"
            FileUtils.touch test_target
          end
        end
      end
    end
  end
end