Add gotestsum

scripts/setup/install-go-gen

@@ -4,3 +4,4 @@ go get -u github.com/gogo/protobuf/proto
 go get -u github.com/gogo/protobuf/jsonpb
 go get -u github.com/golang/protobuf/protoc-gen-go
 go get -u github.com/stevvooe/protobuild
+go get -u gotest.tools/gotestsum