Fixed testing, fixed python3 compatibility, added classifiers for PyPI

- Made it possible to run `python manage.py test` and get passing tests
- Added a `.travis.yml` file to enable Travis CI builds
- Fixed Python 3 compatibility without compromising Django 1.4 compatibility
- Added trove classifiers to `setup.py` for PyPI
```
bash-3.2$ pip freeze |grep Django
Django==1.4.13
bash-3.2$ python
Python 2.7.5 (default, Mar  9 2014, 22:15:05) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> django.VERSION
(1, 4, 13, 'final', 0)
>>> exit()
bash-3.2$ sudo pip install django==1.4
Downloading/unpacking django==1.4
  Downloading Django-1.4.tar.gz (7.6MB): 7.6MB downloaded
  Running setup.py (path:/private/tmp/pip_build_root/django/setup.py) egg_info for package django
    
Installing collected packages: django
  Found existing installation: Django 1.4.13
    Uninstalling Django:
      Successfully uninstalled Django
  Running setup.py install for django
    changing mode of build/scripts-2.7/django-admin.py from 644 to 755
    
    changing mode of /usr/local/bin/django-admin.py to 755
Successfully installed django
Cleaning up...
bash-3.2$ pip freeze |grep Django
Django==1.4
bash-3.2$ python
Python 2.7.5 (default, Mar  9 2014, 22:15:05) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> django.VERSION
(1, 4, 0, 'final', 0)
>>>
```