Added tests for factories/express.

[makara]

@brucefengnju

I have committed many changes after this pull request. Please review this and see if it still works and provide your opinions. If this doesn't work or if you have other ideas, please send me another pull request. If you see something wrong or you have questions, please leave comments here.

[brucefengnju]

@makara The test code still work, and I add two unit tests in the pull request.

I think in the factory/Express.js should check the type of initialize is function.

[makara]

Thanks all. But sorry.