add baxter

python/example_robot_data/robots_loader.py

robots/baxter_description/LICENSE

robots/baxter_description/meshes/base/PEDESTAL.DAE

...axter_description/meshes/base/pedestal_link_collision.DAE

robots/baxter_description/meshes/head/H0.DAE

robots/baxter_description/meshes/head/H1.DAE

robots/baxter_description/meshes/lower_elbow/E1.DAE

robots/baxter_description/meshes/lower_forearm/W1.DAE

robots/baxter_description/meshes/lower_shoulder/S1.DAE

robots/baxter_description/meshes/torso/base_link.DAE

...s/baxter_description/meshes/torso/base_link_collision.DAE

robots/baxter_description/meshes/upper_elbow/E0.DAE

robots/baxter_description/meshes/upper_forearm/W0.DAE

robots/baxter_description/meshes/upper_shoulder/S0.DAE

robots/baxter_description/meshes/wrist/W2.DAE

robots/baxter_description/urdf/baxter.urdf

unittest/test_load.py