fix error

calendar.gemspec

@@ -4,6 +4,7 @@ $:.push File.expand_path("../lib", __FILE__)
 require "calendar/version"
 dir_pwd = ENV['PWD']
 template_path = dir_pwd + '/app/templates'
+app_path = File.expand_path(__dir__)
 all_template = Dir.glob(template_path+'/*/')
 
 puts 'copying calendar module'