log信息：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.breeze.diy.retrofit.demo, PID: 13100
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.breeze.diy.retrofit.demo/com.breeze.diy.retrofit.demo.MainActivity}: java.lang.IllegalArgumentException: Unable to create converter for java.util.List<com.breeze.diy.retrofit.demo.WanAndWXArticle>
解决方法：
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://www.wanandroid.com")
//添加.addConverterFactory()
.addConverterFactory(GsonConverterFactory.create())
.build();
