Make debug arg optional (#8)

Author: guybedford

download-engine.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-set -euo pipefail
+set -eo pipefail
 
 script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"