* upgrade grpc to remove warning
Signed-off-by: YangKeao <keao.yang@yahoo.com>

* make e2e test a standalone module
Signed-off-by: YangKeao <keao.yang@yahoo.com>

* clean the go.mod and go.sum files
Signed-off-by: YangKeao <keao.yang@yahoo.com>

* make check
Signed-off-by: YangKeao <keao.yang@yahoo.com>

* move integration test
Signed-off-by: YangKeao <keao.yang@yahoo.com>

* update e2e-test
Signed-off-by: YangKeao <keao.yang@yahoo.com>

* fix gitignore
Signed-off-by: YangKeao <keao.yang@yahoo.com>
Co-authored-by: Ti Chi Robot <ti-community-prow-bot@tidb.io>