last commit breaks up all pybullet demos

[egordv]

Hello Junhyeokahn and thank you for a great repo! It seems that ad8d19e5f85c721acc6b86b0ff8ce1c9cf5134eb breaks all the demos. At this commit Draco3 demo is falling through the floor just after the simulation starts. Both Atlas demos (dart/pybullet) fails to run with Error reading parameter [n_steps] at file: [PnC/pnc/whole_body_controllers/managers/dcm_trajectory_manager.cpp] At 2ddaa6eb4181f39649dea9dc739727551cd1f988 the situation is better - Atlas demo works as expected, and Draco3 demo is at least able to walk but very unstable leading to a fall after several steps