Decorator to preempt South requirement

def replaced_by_django_migrations(func, *args, **kwargs):
    """Decorator to preempt South requirement"""

    DjangoSettings()  # trigger helpful messages if Django is missing

    import django
    if django.VERSION >= (1, 7):
        print("Django 1.7+ has its own migrations system.")
        print("Use this instead: `invoke managepy makemigrations`")
        sys.exit(1)
    return func(*args, **kwargs)