Id field is not created with AUTOINCREMENT
It appears you are using Sqlite. Please read http://sqlite.org/autoinc.html for an explanation why this is not the default behavior. If you want autoincrement with Sqlite, you can use [PrimaryKeyAutoIncrementField](http://docs.peewee-orm.com/en/latest/peewee/playhouse.html#PrimaryKeyAutoIncrementField) in `playhouse.sqlite_ext`.

I have a normal model and the tables have the ID marked as not AUTOINCREMENT.

This is the code:

``` python
class BaseModel(Model):
    class Meta:
        database = db

class Cobro(BaseModel):
    nombre = CharField()
```

``` sql
CREATE TABLE "cobro"(
    "id"     Integer NOT NULL PRIMARY KEY,
    "nombre" Text NOT NULL )
```
