Major Features and Improvements

Support TO EVALUATE clause to evaluate a model.
SQLFlow model zoo, support publicly share model definitions and models.
Support mathematical programming using SQL.
Support feature column in the XGBoost model, including training, evaluating, prediction, and explaining.
Support incremental training for both TensorFlow and XGBoost models.
Add logs to record runtime status.
Command-line Tool support release/remove model/repo .
Support SHOW TRAIN statement go get original SQL.
Create the SQLFlow Playground as a quick-start environment.

Improvements

Improve the user experience on workflow mode, including improving workflow log structure, return selected rows, and diagnostic message to the GUI system.
Improve some diagnostic messages on the workflow model.
Supports passing all the selected columns into the prediction result table.
Decompose the all-in-one Docker image into separated Docker images.