Finished models definition

Done:
1. Created models in each app, all of which have been validated.
2. Completed main URL configuration so that all the requests will be
dispatched to the right app.
3. Add index.wsgi file so that this project can run on the SAE.
4. Add static and templates folder
5. Finished the outlines of the whole project
Hasn't implemented:
1. The methods in the models