参考资料：
[AngularJS系列(4)] 那伤不起的provider们啊~ (Provider, Value, Constant, Service, Factory, Decorator)：http://hellobug.github.io/blog/angularjs-providers/
Single Page Apps with AngularJS Routing and Templating：https://scotch.io/tutorials/single-page-apps-with-angularjs-routing-and-templating
How to Implement Safe Sign-In via OAuth：http://devcenter.kinvey.com/angular/tutorials/how-to-implement-safe-signin-via-oauth
A Better Way to Learn AngularJS：https://thinkster.io/a-better-way-to-learn-angularjs
$http Interceptors：https://thinkster.io/a-better-way-to-learn-angularjs/interceptors
Simple AngularJS Authentication with JWT:https://thinkster.io/angularjs-jwt-auth#authenticating-with-an-interceptor
Implementing Authentication in Angular Applications:https://www.sitepoint.com/implementing-authentication-angular-applications/
Angularjs中的拦截器 （卧槽，好牛逼）:
Interceptors in AngularJS and Useful Examples:http://www.webdeveasy.com/interceptors-in-angularjs-and-useful-examples/
angularJS 1.5.7官方文档：https://code.angularjs.org/1.5.7/docs/api
