Removing unused folders
Adding unit tests
No need for testing in this file anymore
Removing errors field in cronmanager table because there is no need for this field -> you can get the number of errors by counting the errors pointing to this manager
Removing CronManager errors field and CronError rundate because this fields are not needed
Extend logging
Cleaning code
Removing rundate field from the CronError table because there is no need for this field -> use the rundate of the parant CronManager