v2.2.0

High Level

• Added Generative Augmented Flow Networks example (https://arxiv.org/abs/2210.03308), which specifies intermediate rewards with intrinsic motivation to help with the exploration problem in sparse reward environments.
• Extended graph functionality (e.g., add nodes as an action).
• More efficient autoregressive GFN training.

What's Changed

• Add GAFN for hypergrid with sparse reward by @hyeok9855 in #375
• Add graph example with add node action by @younik in #378
• Misc efficiency improvements by @hyeok9855 in #376
• Simplify GraphActionGNN by @younik in #382
• Don't allow removal of nodes with edges by @younik in #381
• minor change to allow for pb to be None when the gflownet's DAG is a tree by @josephdviviano in #371

Full Changelog: v2.1.1...v2.2.0