Merge pull request #564 from gabrielebndn/topic/fixunittest

doc/d-labs/src/pendulum.py

doc/d-labs/src/robot_hand.py

examples/python/fd-derivatives.py

examples/python/id-derivatives.py

examples/python/kinematics-derivatives.py

models/simple_model.py

src/parsers/sample-models.cpp

src/parsers/sample-models.hpp

unittest/python/bindings_SE3.py

unittest/python/bindings_force.py

unittest/python/bindings_frame.py

unittest/python/bindings_geometry_object.py

unittest/python/bindings_geometry_object_urdf.py

unittest/python/bindings_inertia.py

unittest/python/bindings_motion.py

unittest/python/model.py

unittest/python/tests.py

unittest/sample-models.cpp