Cron run manually

Reopening https://github.com/OCA/server-tools/pull/58. Tests will fail. The error is [when creating a fake user](https://travis-ci.org/OCA/server-tools/jobs/35619814#L560), but I copied it from [the account module](https://github.com/odoo/odoo/blob/master/addons/account/test/account_test_users.yml#L4), I don't understand the failure.

In my manual tests, the module works so if you can help me patch the tests, I will be glad to do it. Otherwise, I can remove it and it can be merged without the test.

Thanks and sorry for the noise.