before:
```
8.9M robots/asr_twodof_description/qb_meshes/dae/qbmove_frame_m.dae
7.2M robots/baxter_description/meshes/electric_gripper/electric_gripper_w_fingers.DAE
4.9M robots/baxter_description/meshes/torso/base_link.DAE
 88M robots/go1_description/meshes/trunk.dae
```

after:
```
1.7M robots/asr_twodof_description/qb_meshes/dae/qbmove_frame_m.dae
2.2M robots/baxter_description/meshes/electric_gripper/electric_gripper_w_fingers.DAE
2.6M robots/baxter_description/meshes/torso/base_link.DAE
 28M robots/go1_description/meshes/trunk.dae
```

for more information, see https://pre-commit.ci

for more information, see https://pre-commit.ci

Resolves #146

for more information, see https://pre-commit.ci

Created the Gazebo URDF from upstream franka_description package and
then manually merged the inertials and new TCP frame into our packaged
URDF. Should fix #122

Note: There are two types of URDFs in the upstream repository. One also
has simplified, larger collision shapes. Since we possibly want to
simulate using the URDFs here, I kept the configuration using the convex
meshes rather than primitive shapes.

for more information, see https://pre-commit.ci

Adds BSD-3 licensed ANYmal C simple description from
https://github.com/ANYbotics/anymal_c_simple_description commit
f119c8f3c4b9e08948b0f5915e9c7cedf63f52e5

Modified to:
1. Fix the path for mesh loading
2. Add SRDF

for more information, see https://pre-commit.ci

* cassie/cassie_v2 sdf: remove first primatic joint, add color information

* robots_loader: use updated sdf parser for pin version > 2.9.1

* cassie srdf: update joint info, add missing joints

Co-authored-by: Rohan Budhiraja <proyan@users.noreply.github.com>

* simple_humanoid: add mesh, update srdf with rotor info, urdf with colliison info

* simple_humanoid: fix mesh path

Co-authored-by: Rohan Budhiraja <proyan@users.noreply.github.com>

* Add simplified double pendulum

* Add description to urdf, loader and unittest

* Fix format

* Fix format for unittest

* double pendudum: update credits

Co-authored-by: Justin Beri <justin [dot] beri [at] csiro [dot] au>
Co-authored-by: Justin Beri <justin.beri at hdr.qut.edu.au>
Co-authored-by: Guilhem Saurel <guilhem.saurel@laas.fr>