[Feature Request] Trainer saving and loading utils

[vmoens]

The Trainer class supports saving model and environment variables in order for them to be re-used. However this workflow is still experimental.
Eventually, it should be possible to save and load an agent state and restart training where it was left.

[Benjamin-eecs]

Now that agent class is gone, I think it is safe to close this issue.

[vmoens]

You're right. We should edit it with Trainer instead

[Benjamin-eecs]

I think it can be considered done in trainer class.