Flake8
Added python-dateutil to setup.install_requires.
Using dateutil to parse datetime strings provided by Postmark as the format appears to have changed and this is just easier.
Moved migrations to south_migrations so that we can support both South and Django migrations.
Added initial migration for Django migrations.
Set default value for BooleanFields as per Django 1.6; w/ migration.
Upped version.
Merge branch 'release/django-16'