added class to represent user

src/app/account/user.spec.ts

@@ -0,0 +1,7 @@
+import { User } from './user';
+
+describe('User', () => {
+  it('should create an instance', () => {
+    expect(new User()).toBeTruthy();
+  });
+});

src/app/account/user.ts

@@ -0,0 +1,6 @@
+export class User {
+  id: number;
+  username: string;
+  email: string;
+  token: string;
+}