Reorganize Project using Yeoman

Pull Request for https://github.com/guitar-academy/gaclient/issues/18

- [x] Reorganize Project
- [ ] Bug Clear (Please check for your component, ensure its still working)
I'm not sure if it is important. Most of these are automatically generated during the yeoman initialization process. 

`gaserver` is to serve the API and at the moment we use apache. 
`gaclient` is to serve the guitar academy client. It may use apache, nginx, S3, dropbox, or anything else.

It is two independent web project. Each of them has to be served.

So i think this file doesn't do anything as of now. But may be useful if we use apache to serve gaclient.
What do you think? (shall we keep this file for now?)