Modify output_env.sh to make it extensible
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index bd8d6d3..e16c1b5 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#! /usr/bin/env sh
 
 # all.sh
 #