Update test exclude cmd subdir

Makefile

@@ -5,7 +5,7 @@ update:
 	go mod tidy
 
 test:
-	go test -cover $(shell go list ./... | grep -v /vendor/ | grep -v /build/) -v -coverprofile=coverage.txt -covermode=atomic
+	go test -cover $(shell go list ./... | grep -v /vendor/ | grep -v /build/ | grep -v /cmd/) -v -coverprofile=coverage.txt -covermode=atomic
 	go tool cover -html=coverage.txt -o coverage.html
 
 mnist: