change make generate to use docker run to be more protable

Makefile

@@ -1,3 +1,4 @@
+BUILDER := docker run --rm -it --workdir /data -v ${PWD}:/data debian:8 ./hack/scripts/generate-manifests.sh
 generate:
 	@echo ">> Compiling assets and generating Kubernetes manifests"
-	@hack/scripts/generate-manifests.sh
+	$(BUILDER)