Adding three different mo-mountain-car environments

[pranavg23]

Environments added with relevant comments:
1)Time-Speed (2 Objectives)
2)Time-Movement (2 Objectives)
3)Time-Movement-Speed (3 Objectives)

[LucasAlegre]

@pranavg23 I simplified the code since the computation of the rewards was very simple. Can you check if this is still equivalent to your version?

[pranavg23]

The 3 objective setting has a merged movement objective and a speed objective, while I think the change you made, adds just a speed objective which would make it 4 objective. @LucasAlegre

No reward setting has forward and backward rewards, they are either combined or removed (time-speed) case, since they give rise to the local optima due to a lack of reward signal for the static action

[LucasAlegre]

@pranavg23 thanks! I think I fixed it in the last commit. Could you double-check?

[pranavg23]

@pranavg23 thanks! I think I fixed it in the last commit. Could you double-check?

Just checked, all good!