primary_key on sqlite seems to make table not saveable
force_insert=True

Potentially related to my other issue log. I've found that if I set a column to primary_key=true (I've tried this on a CHAR and UUID columns), I don't get any errors, but the "save()" method returns 0:

class SimpleTest(BaseModel):
  name = CharField(primary_key=True)
  name2 = CharField()

simple = SimpleTest(name="Charlie", name2="Bucket")
print("Saving %d simples" % simple.save())

running this yields:

Saving 0 simples

No compile time errors or other messages.

I've then logged into the sqlite file directly and not surprisingly, I see no rows when selecting from the table.

Apologies if these are already logged--I did some searching and all I found was a comment from you about a year ago discussing the "primary key as only column" on a forum post...
