make-sqlite reports table is locked

When run `TestCreateFile` or `TestCreateFileOnProtectedBranch`, it reports,
```
2017/05/05 10:07:21 [...ea/models/webhook.go:641 DeliverHooks()] [E] UpdateWebhook: database table is locked
2017/05/05 10:07:21 [.../runtime/asm_amd64.s:2197 goexit()] [E] UpdateHookTask [2]: database table is locked
```
This will not stop the tests but it needs to be fixed.