fix makefile s/setuptools/pkg_resources/

Makefile

@@ -2,6 +2,6 @@ empty:
 	exit 1
 
 update-vendored:
-	rm -rf setuptools/_vendor/packaging
-	pip install -r setuptools/_vendor/vendored.txt -t setuptools/_vendor/
-	rm -rf setuptools/_vendor/*.{egg,dist}-info
+	rm -rf pkg_resources/_vendor/packaging
+	pip install -r pkg_resources/_vendor/vendored.txt -t pkg_resources/_vendor/
+	rm -rf pkg_resources/_vendor/*.{egg,dist}-info