- Add uplift_tree_plot() to inference.tree to visualize UpliftTreeClassifier by @zhenyuz0500
- Add the Explainer class to inference.meta to provide feature importances using SHAP and eli5's PermutationImportance by @yungmsh
- Add bootstrap confidence intervals for the average treatment effect estimates of meta learners by @ppstacy
- Extend meta-learners to support classification by @t-tte
- Extend meta-learners to support multiple treatments by @yungmsh
- Fix a bug in uplift curves and add Qini curves/scores to metrics by @jeongyoonlee
- Add inference.meta.XGBRRegressor with early stopping and ranking optimization by @yluogit
- Add optimize.PolicyLearner based on Athey and Wager 2017 :cite:`athey2017efficient`
- Add the CausalTreeRegressor estimator based on Athey and Imbens 2016 :cite:`athey2016recursive` (experimental)
- Add missing imports in features.py to enable label encoding with grouping of rare values in LabelEncoder()
- Fix a bug that caused the mismatch between training and prediction features in inference.meta.tlearner.predict()
- Initial release with the Uplift Random Forest, and S/T/X/R-learners.