Simplify CRD definition

[yorugac]

Right now, to have any new feature native to Kubernetes jobs we have to add it manually, option by option. Consider how to improve this approach. Some preliminary ideas:

• import of definitions
• use of PodTempate
• ?

This might come up in code refactoring too, but it might be a breaking change (due to potential change of yaml definition). So perhaps, best to keep it separate from non-breaking refactoring.