[DEV] Use model path in sdf meshes

[lokiledev]

fix #15

The name of the folder containing the config.json file should be the same as the robot name. Maybe we can do better, but I got gazebo and ros to find the model and meshes with this.

[Gregwar]

Hello,
In that case, why wouldn't we use the name of the folder containing config.json instead ?

[lokiledev]

Yes totally It would make more sense.

[lokiledev]

Hello,
In that case, why wouldn't we use the name of the folder containing config.json instead ?

I've done the change so that the name of the folder is used.