Checking space constrains

[RobinU434]

Dear development team,

during this years edition of the rl project, we made a stupid mistake, and we predicted actions outside the boundaries of the environment. We noticed this bug by only looking into individual actions. But you could also intercept this in the step function by checking if the action space contains the given action.
Is there a reason why this is not implemented?

I you wish I will open up a pull request shortly with the necessary changes.

Further, we noticed that shooting is not symmetric given the Box(-1,1), but the decision boundary lies at 0.5. Again, is there a reason for it?

All the best,
Robin