Add cassie robot in example-robot-data (#100)

* [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>
10 jobs for devel in 1 minute and 36 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Test
passed doc-coverage #130379

00:01:14

passed format #130380

00:00:23

passed robotpkg-example-robot-data-18.04 #130371

00:00:35

passed robotpkg-example-robot-data-20.04 #130372

00:00:13

passed robotpkg-example-robot-data-buster #130373

00:00:34

passed robotpkg-example-robot-data-ferrum #130374

00:00:20

passed robotpkg-py-example-robot-data-18.04 #130375

00:00:36

passed robotpkg-py-example-robot-data-20.04 #130376

00:00:37

passed robotpkg-py-example-robot-data-buster #130377

00:01:06

passed robotpkg-py-example-robot-data-ferrum #130378

00:01:35