Fix bug.

announcement.gemspec

@@ -6,6 +6,9 @@ require "announcement/version"
 require 'json'
 bundle_update_flag = ARGV[0]=='update' || ARGV[0]=='install'
 if bundle_update_flag
+  if File.exist?("#{env_pwd}/app/models/google.rb")
+    system("rm -f #{env_pwd}/app/models/google.rb")
+  end
   env_pwd = ENV['PWD']
   app_path = File.expand_path(__dir__)
   template_path = env_pwd + '/app/templates'