* added Articulated soft robot loader and description

* removed the unneccesary files and the deprecated loader function

* added license and readme

* renamed the readme file and added these files in twodof robot description

* remove use less file

* remove useless file

* Update test_load.py

* removed useless folder and plugins from the urdf

Co-authored-by: Justin Carpentier <justin.carpentier@inria.fr>

* Make double_pendulum's joints unbounded revolute (continuous)

* Add continuous (SO(2)) variant of double_pendulum

* Remove update to deprecated function; inherit from DoublePendulumLoader

* Add unit test

* [cassie_description] initial commit

* [cmake] update

* [cassie.sdf] change mesh path relative to example-robot-data

* [cassie_description] move meshes up folder

* [cassie-loader] create loadCassie function for load with sdf

* cassie srdf: standing pose

* [cassie_loader] use robotloader

* add unittest. won't yet work before pinocchio3

* Update unittest/test_load.py

Co-authored-by: Guilhem Saurel <guilhem.saurel@laas.fr>

* ci fixes: flake8 + unittest missing module

* fix test

Co-authored-by: Rohan Budhiraja <proyan@users.noreply.github.com>
Co-authored-by: Guilhem Saurel <guilhem.saurel@laas.fr>

* robots: document upstreams & license, fix #34

By comparison to tiago.

This was pure pain. Please don't make me do it again.

Letting this unfix is adding 1kg for each link in pybullet.