SQL to migrate the DB. Create migrations, migrate
`DELETE FROM django_content_type WHERE app_label='thoughts';`
`UPDATE django_content_type SET app_label='thoughts' WHERE app_label='main';`
`DROP TABLE thoughts_thought;`
`ALTER TABLE main_thought RENAME TO thoughts_thought;`
`DELETE FROM django_migrations WHERE app='main';`
Hopefully that's right, I'm not going to double check it or anything.
