Finish the model for simulation

[carlosjoserg]

The main idea is to have the two available modes from the hardware in simulation, that is, rigid parallel gripper, or adaptive gripper.

The idea is to add all the transmission computations in the hardware abstraction, or create a gazebo hardware interface similar to the usb interface

low_priority

[carlosjoserg]

50% done.. https://github.com/beta-robots/robotiq/tree/new_2_finger_models/robotiq_2f_model#simulation-on-gazebo