Code review comment for lp:~wgrant/launchpad/sprb-new-model-columns

Looks good, thanks for this. Just a couple of comments:

1. s/exist/exists/ in the assertion text message.
2. You get brownie points if you can remove the commit from the tests - we found out that they slow the tests down massively so now I am on a jihad against them. Try using store.flush() or if that fails, try store.commit() as it's a bit closer to the metal than transaction.commit()