Python 3.*/Django 1.5+ support. 

1. ``Python 3.*/Django 1.5+`` support. 
2. Avoid new redis connection each request, its very useful on service like heroku with limited redis connection
3. Test moved outside ``redis_sessions`` package
4. Small pep8 fixes
5. Refactored ``getattr``
6. Bump version
7. travis-ci build https://travis-ci.org/hellysmile/django-redis-sessions/builds/5088100

PS; currently travis-ci is overloaded, but according to previous commit everything is ok, except ``Django<1.4``