Make position accessible

[eugenevinitsky]

@daphnecor, I realized that the expert positions were actually not accessible!

[aaravpandya]

I think this is already working with your changes. I did the following and can get an output -

env.scenario.expert_position(env.scenario.getObjects()[0], 0)

returns a tuple like '(9032.836914, -2718.306396)`

[eugenevinitsky]

Cool, then we can merge it!

[daphnecor]

Nice, thanks!