Update settings.py

Added check to set DEBUG to False on Openshift production environment and DEBUG to True for development environment
Fixed Django requirement causing Server Error 500

The previous install requirement 'Django>=1.3' was installing Django 1.5.1, which resulted in an internal server error 500.  I adjusted to 'Django<=1.4', 1.4 was the most recent version I found immediately compatible when testing.
Merge pull request #17 from iepathos/master

Just added simple check to improve default settings