[bug report (Environment)] RELATIVE_POS=False doesn't work as expected

[ncble]

Describe the bug

Taking MobileRobotGymEnv-v0 as example:
When setting RELATIVE_POS=False, the method getGroundTruthDim still return 2 as ground truth dimension, only the robot position is returned. In particular, this is wrong under the random target setting, since the ground truth should be 4 dimensional.

This problem appears for all environments.

p.s. problem already fixed in my pull request