Add -race option to make test

Author: kl52752

Makefile

@@ -30,7 +30,7 @@ build: gen
 test: gen
 	# Test only the library. e2e must be run in a special environment,
 	# so is skipped.
-	go test ./pkg/...
+	go test -race ./pkg/...
 	# We cannot use golint currently due to errors in the GCP API naming.
 	# golint ./...
 	go vet ./...