added south app and requirement

* created a develop branch for everyone to be able to contribute features and then we can port everything to master when they work

this feature branch is to add [South](http://south.readthedocs.org/en/latest/tutorial/part1.html)

it's very helpful when making changes to the model and ensuring that all of our databases are consistent.

after merging this branch, run the following commands to port your existing apps to South. 

```
python manage.py syncdb
python manage.py convert_to_south reservations
python manage.py migrate reservations
```