Django 1.7 incompatibility when installing from scratch

I received the following error, which was fixed by downgrading to Django 1.6.

I got to this point by following the readme instructions, so it's a vanilla set up.

```
$ python ./manage.py syncdb
System check identified some issues:

WARNINGS:
?: (1_6.W001) Some project unittests may not execute as expected.
	HINT: Django 1.6 introduced a new default test runner. It looks like this project was generated using Django 1.5 or earlier. You should ensure your tests are all running & behaving as expected. See https://docs.djangoproject.com/en/dev/releases/1.6/#new-test-runner for more information.
Syncing...
Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/admin/workspace/djangothing/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/Users/admin/workspace/djangothing/lib/python2.7/site-packages/django/core/management/__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/admin/workspace/djangothing/lib/python2.7/site-packages/django/core/management/base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Users/admin/workspace/djangothing/lib/python2.7/site-packages/django/core/management/base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "/Users/admin/workspace/djangothing/lib/python2.7/site-packages/django/core/management/base.py", line 533, in handle
    return self.handle_noargs(**options)
  File "/Users/admin/workspace/djangothing/lib/python2.7/site-packages/south/management/commands/syncdb.py", line 82, in handle_noargs
    old_app_store, cache.app_store = cache.app_store, SortedDict([
AttributeError: 'Apps' object has no attribute 'app_store'
(djangothing)Admins-MacBook-Air:djangothing admin$ pip install -r requirements/local.txt
Requirement already satisfied (use --upgrade to upgrade): django in ./lib/python2.7/site-packages (from -r requirements/base.txt (line 5))
Requirement already satisfied (use --upgrade to upgrade): django-model-utils in ./lib/python2.7/site-packages (from -r requirements/base.txt (line 7))
Requirement already satisfied (use --upgrade to upgrade): psycopg2 in ./lib/python2.7/site-packages (from -r requirements/base.txt (line 9))
Requirement already satisfied (use --upgrade to upgrade): South in ./lib/python2.7/site-packages (from -r requirements/base.txt (line 10))
Requirement already satisfied (use --upgrade to upgrade): Pillow in ./lib/python2.7/site-packages (from -r requirements/base.txt (line 12))
Requirement already satisfied (use --upgrade to upgrade): mock in ./lib/python2.7/site-packages (from -r requirements/testing.txt (line 3))
Requirement already satisfied (use --upgrade to upgrade): model-mommy in ./lib/python2.7/site-packages (from -r requirements/testing.txt (line 4))
Requirement already satisfied (use --upgrade to upgrade): Sphinx in ./lib/python2.7/site-packages (from -r requirements/local.txt (line 3))
Cleaning up...
```