Make sure packs directory exists

Author: React-Admin CI

Makefile

@@ -192,4 +192,5 @@ release: ## Start the release process and publish the packages to npm using lern
 	./scripts/release.sh
 
 pack: ## Create NPM packages for all publishable packages in ./packs
+	mkdir -p packs
 	yarn workspaces foreach -A --no-private pack --out ../../packs/%s-%v.tar.gz