Can't install with -e using 2to3 on travis

Author: jpic

.travis.yml

@@ -9,7 +9,7 @@ install:
   - pip install -q Django==$DJANGO --use-mirrors
   - pip install pep8 --use-mirrors
   - pip install https://github.com/dcramer/pyflakes/tarball/master
-  - pip install -q -e . --use-mirrors
+  - python setup.py install
   - pip install south mysql-python psycopg2
 before_script:
   - "pep8 --ignore=E124,E128 --exclude=tests,migrations cities_light"