Implement Successor Options

[tmssmith]

Describe You Feature
Replicate Ramesh et al. (2019) paper, code

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
In order of priority:

1. Base Successor Options
2. Incremental Successor Options
3. Non-uniform and Adaptive-Exploration Successor Options

Additional context
The exploration methods described in (3) above may not be relevant to epoch-based evaluation (with $\epsilon=0$). Further, exploration strategies may be better implemented at the agent level not the option level.