如何从Django 1.7中的初始迁移返回?

I created a new app with some models and now I noticed that some of the models are poorly thought out. As I haven't committed the code the sensible thing would be to migrate the database to last good state and redo the migration with better models. In this case the last good state is database where the new app doesn't exist.I created a new app with some models and now I