feat(): add plain-service and json-service export

测试需要真实的类，type不能作为sinon的参数，因为js运行时不存在

Author: toonew

lib/index.ts

@@ -1,6 +1,10 @@
 /**
  * Created by Rain on 2020/3/30
  */
+
+export * from './services/json-logger.service';
+export * from './services/plain-logger.service';
+
 export * from './interfaces';
 export * from './constant';
 export * from './logger.module';