add support for property

In our scene, we sometimes use `muk` like this:  
```js
describe('#func', function () {
  afterEach(muk.restore);
  it('response mock data', function () {
    muk(config, 'cache', false);
    //do the test
  });
});
```

We sometimes use `muk` for mock property, so that we can use `muk.restore` to restore all the mocked method and properties.