some issues in team_code_v2

[MingfeiCheng]

Hi,

Thanks for sharing this project. While configuring and running it, I noticed a couple of small issues in team_code_v2 that might cause errors.

1. TypeError in aim assignment https://github.com/dotchen/LAV/blob/12540bd5f7b8a1059117681fa8e1fa00e8908dd7/team_code_v2/lav_agent.py#L411

This raises

aim = waypoints[self.aim_point[cmd]]
TypeError: 'int' object is not subscriptable

This can be fixed by aligning with team_code/lav_agent.py

aim = waypoints[self.aim_point]

2. AttributeError in lav_agent and lav_agent_fast

AttributeError: 'LAVAgent' object has no attribute 'speed_ratio'

The corrsponding code: https://github.com/dotchen/LAV/blob/12540bd5f7b8a1059117681fa8e1fa00e8908dd7/team_code_v2/lav_agent.py#L419

I removed self.speed_ratio[cmd], following the implementation in team_code/lav_agent.py.

I am not certain whether this is a minor typo or if it has an impact on the performance of the ADS.

Thank you.