update test_stiffness_tensors()
update test_stiffness_tensors()

rc/sfepy,lokik/sfepy,vlukes/sfepy,vlukes/sfepy,lokik/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,BubuLK/sfepy,lokik/sfepy,BubuLK/sfepy,sfepy/sfepy,sfepy/sfepy,RexFuzzle/sfepy,rc/sfepy,sfepy/sfepy,RexFuzzle/sfepy,lokik/sfepy,rc/sfepy,RexFuzzle/sfepy,vlukes/sfepy