Shift Travis away from using Tox.

.travis.yml

@@ -1,6 +1,12 @@
 language: python
 python:
   - 3.3
+  - 2.7
+env:
+  - ADDITIONAL_REQUIREMENTS='django>=1.6,<1.7 south>=0.8'
+  - ADDITIONAL_REQUIREMENTS='django>=1.6,<1.7'  
+  - ADDITIONAL_REQUIREMENTS='django>=1.5,<1.6 south>=0.8'
+  - ADDITIONAL_REQUIREMENTS='django>=1.5,<1.6'
 addons:
   postgresql: 9.2
 branches:
@@ -12,11 +18,14 @@ install:
   - pip install --upgrade setuptools pip
   - pip install -r requirements.txt
   - pip install -r tests/requirements.txt
+  - pip install $ADDITIONAL_REQUIREMENTS
   - pip install coveralls
 
   # Create our database.
   - psql -U postgres -c 'create database django_pg;'
   - psql -U postgres -d django_pg -c 'create extension postgis;'
-script: python setup.py test
+script:
+  - coverage run -p tests/runtests.py
+  - coverage run -p tests/runtests.py gis
 after_success:
   - coveralls