add metrics in XLDST evaluation (#126)

* update sumbt translation train result with evaluation mode set

* update extract values

* automatically download sumbt model

* dstc9 eval

* dstc9 xldst evaluation

* modify example

* add .gitignore

* remove precision, recall, f1

* release 250 test data

* revise evaluation

* fix file submission example

* update precision, recall, f1 calculation

* minor change