Allow to validate empty values #1
Description
At the moment the validator is not able to validate empty values.
Those you need to validate with Flows NotEmpty in addition. This is breaking the idea to configure the validation via a yaml file.
As this change will be breaking. We should release it as 2.x and keep 1.x as it is.
New features can be added to both versions, as the change should be very small and those easy to merge with future changes.