fix empty directory check for OS X and BSD

`ls` on those systems only recognizes short form flags
fixes main problem of #17

Author: X1011

deploy.sh

@@ -60,8 +60,9 @@ main() {
 		echo "Deploy directory '$deploy_directory' does not exist. Aborting." >&2
 		return 1
 	fi
-
-	if [[ -z `ls --almost-all "$deploy_directory" 2> /dev/null` && -z $allow_empty ]]; then
+	
+	# must use short form of flag in ls for compatibility with OS X and BSD
+	if [[ -z `ls -A "$deploy_directory" 2> /dev/null` && -z $allow_empty ]]; then
 		echo "Deploy directory '$deploy_directory' is empty. Aborting. If you're sure you want to deploy an empty tree, use the --allow-empty / -e flag." >&2
 		return 1
 	fi