Use github.com/wangkuiyi/tar (#91)
Use github.com/wangkuiyi/tar (#91)

* Add a design draft

* Use github.com/wangkuiyi/tar

* Use the `if e :=` pattern

* should return nil if train success

sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow,sql-machine-learning/sqlflow