Should action_space and observation_space be instances of gym.spaces.Space?
action_space and observation_space are currently (v0.2) not of type gym.spaces.Space. Also the action_space is always set to [1] which surprises me. Is this the intended behavior?
See https://gitlab.aicrowd.com/flatland/flatland/blob/master/flatland/envs/rail_env.py#L123