change version to 2.0.1

add v2.0.0

Feat/fix examples (go-kratos#1129)

remove github protobuf dependency

fix version (go-kratos#1090)

add examples/errors (go-kratos#1077)

* addd examples/errors

fix wrapper seq (go-kratos#1073)

test http (go-kratos#1045)

* test http
* fix response codec
* benchmark

copy errors proto (go-kratos#1030)

change filename

log: rename Print to Log (go-kratos#886)

* rename Print to Log