Command.ownProperties must be definead in __init__
+ add test for this
Change-Id: I283331be6439a49ec61d28f04869a5b44704236f
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/27104
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>