Observation space

[emilio-cartoni]

A few issues have been raised about the observation space:

• it is not passed to the Controller (unlike the action space)
• the observation space does not contain goal_positions observation
• the environment returns 'object_positions' as a position (array(3,)) while the observation space defines a pose (array(7,))

See: https://discourse.aicrowd.com/t/wrappers-using-observation-space-access/3597/3