remove temp dir after zip file is created

Author: knoxfighter

Makefile

@@ -18,6 +18,7 @@ build/factorio-server-manager-%.zip: clean app/bundle factorio-server-manager-%
 @cp -r app/ factorio-server-manager/
 @cp conf.json.example factorio-server-manager/conf.json
 @zip -r $@ factorio-server-manager > /dev/null
+@rm -r factorio-server-manager/
 
 app/bundle:
 @echo "Building Frontend"