Add a test about UpdateCauchyGreenTensor operator
There are none currently, and it is used in the Poromechanics model (where incidentally it doesn't compile so I want to make sure the class works in the first place in current MoReFEM)
There are none currently, and it is used in the Poromechanics model (where incidentally it doesn't compile so I want to make sure the class works in the first place in current MoReFEM)