Asimmetry of ~0.1 millimeters between the soles of iCubGazeboV2_5 in x and y direction

[traversaro]

See https://github.com/robotology/icub-model-generator/pull/122#issuecomment-536451721 .

[traversaro]

There is also a small assimettry on the y (see https://travis-ci.org/robotology/icub-model-generator/builds/604550171?utm_source=github_status&utm_medium=notification)

icub-model-test : base_link test performed correctly 

icub-model-test error: l_sole_y is -0.0701752, while r_sole_y is 0.0700861 while they should be simmetric (diff : 8.91e-05 )

      Start  7: iCubGazeboV2_5_plusConsistencyCheck

 7/11 Test  #7: iCubGazeboV2_5_plusConsistencyCheck ...   Passed    0.03 sec

      Start  8: iCubGenova01ConsistencyCheck

 8/11 Test  #8: iCubGenova01ConsistencyCheck ..........***Failed    0.02 sec

icub-model-test : base_link test performed correctly 

icub-model-test error: l_sole_y is -0.0701752, while r_sole_y is 0.0700861 while they should be simmetric (diff : 8.91e-05 )

      Start  9: iCubGenova02ConsistencyCheck

 9/11 Test  #9: iCubGenova02ConsistencyCheck ..........   Passed    0.04 sec

      Start 10: iCubGenova04ConsistencyCheck

10/11 Test #10: iCubGenova04ConsistencyCheck ..........***Failed    0.02 sec

icub-model-test : base_link test performed correctly 

icub-model-test error: l_sole_y is -0.0701752, while r_sole_y is 0.0700861 while they should be simmetric (diff : 8.91e-05 )

      Start 11: iCubDarmstadt01ConsistencyCheck

11/11 Test #11: iCubDarmstadt01ConsistencyCheck .......***Failed    0.02 sec

icub-model-test : base_link test performed correctly 

icub-model-test error: l_sole_y is -0.0701752, while r_sole_y is 0.0700861 while they should be simmetric (diff : 8.91e-05 )