feat: provide abstract class baseService

Author: wewoor

src/services/baseService.ts

@@ -0,0 +1,8 @@
+export abstract class BaseService {
+    /**
+     * Subscribe the service event
+     * @param name Event name
+     * @param callback Callback function
+     */
+    public abstract subscribe(name: string | string [], callback: Function);
+}