Hice syncdb (aplicación Python / Django) en Heroku y él creó la tabla south_migrationhistory,

(venv-project)username@username:~/projectapp$ heroku run python manage.py syncdb
Running `python manage.py syncdb` attached to terminal... up, run.5529
Syncing...
Creating tables ...
Creating table auth_permission
Creating table auth_group_permissions
Creating table auth_group
Creating table auth_user_groups
Creating table auth_user_user_permissions
Creating table auth_user
Creating table django_content_type
Creating table django_session
Creating table django_site
Creating table django_admin_log
Creating table south_migrationhistory

(...)

Synced:
 > django.contrib.auth
 > django.contrib.contenttypes
 > django.contrib.sessions
 > django.contrib.sites
 > django.contrib.messages
 > django.contrib.staticfiles
 > django.contrib.admin
 > south

Not synced (use migrations):
 - core
 - galeria
(use ./manage.py migrate to migrate these)

pero cuando migre la aplicación, dice que la tabla no se creó:

(venv-project)username@username:~/projectapp$ heroku run python manage.py migrate core
Running `python manage.py migrate core` attached to terminal... up, run.7542

(... registro monstruoso ...)

File "/app/.heroku/python/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py", line 337, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.DatabaseError: no such table: south_migrationhistory

¿Que puede ser? Gracias.

EDITAR: Resuelto, puse en settings_local gitignore y con ello reconocí la base de datos postgres heroku.