Updating tutorial for Django 1.6

[willingc]

All tutorial code worked with Django 1.6.

Differences identified from 1.5 to 1.6:

• Update requirements.txt for 1.6
• Database defaults to SQLite in settings.py
• Admin is automatically added to INSTALLED_APPS in settings.py

[treyhunner]

Another difference:

The BASE_DIR variable seems to already be present in the settings.py file.

• Remove BASE_DIR

[davidfischer]

• Change links to point to Django 1.6 docs
• Check for other changes in settings.py
• Python 2.6.5 or 2.7 is required. While Python 3.3+ will work, it is not recommended for this tutorial