fix:can't find image
Merge branch 'mia_dev' into dev
merge mia
rm main.js since it merge into script.js
add db seed file to generate testing data.
update testing data: create four user, create a group contain those four users.
add script to gen testing data.
since ajax request will replace the POST to OPTIONS, OPTION method add to route
allow the cross domain request
add some enhance
add the doc of how I deploy website on aliyun.
Merge branch 'minghe_dev' into dev

Conflicts:
	app/controllers/application_controller.rb
	config/routes.rb
	config/secrets.yml
	db/seeds.rb
	public/app/css/styles.css
	public/index.html
	public/javascript/main.js
	public/javascript/script.js
	tools/gen_tesing_data.sh
Merge branch 'dev' of https://github.com/us4us/seed into dev
finished the user/:user_id/groups and the group/:group_id/users
merge dev