Proximal Policy Optimization - Week 4

This week, I mainly focus on Proximal Policy Optimization pull request.

• Added Step and Episode function in PPO algorithm.
• Added initial test case for the PPO algorithm.
• Opened a PR for the the pendulum environment.
• Added action prediction in the PPO algorithm.

I choose the continuous task, pendulum, to test the PPO algorithm, it seems that some code in the original code base did not support the continuous task. Next week, I will change that one.

Thanks for reading :).