test_crontabber_state assumed that the crontabber_state contained something

When I added the test_crontabber_state I used an existing postgres that had something in the `crontabber_state` table. 

If you run a fresh `setupdb_app.py --dropdb ...` it will create a `crontabber_state` table but it contains no rows. 

Arguably, perhaps this is a bug in setupdb_app and the fact that the create table should be followed by an initial insert to `crontabber_state`

r? @selenamarie @rhelmer