Transaction Conflict in tests

[merlinran]

This happens in tests here as well as the auction system CI

setting proposal cid: committing txn: Transaction Conflict. Please retry

It's caused by a race between txn.Commit at https://github.com/textileio/bidbot/blob/main/service/store/store.go#L372 and the call to s.saveAndTransitionStatus in the fetch worker https://github.com/textileio/bidbot/blob/main/service/store/store.go#L615 which triggered by sending to jobCh https://github.com/textileio/bidbot/blob/main/service/store/store.go#L536

In reality it shouldn't be a problem because it takes some time to download and import data, but the mocked calls return immediately, allow them to run nearly the same time.