Add placeholder tests.sh script

Change-Id: Id14b3f38099cfcd566ba63106d435c7f93b3d3c0
Reviewed-on: https://fuchsia-review.googlesource.com/c/shac-project/shac/+/820047
Fuchsia-Auto-Submit: Oliver Newman <olivernewman@google.com>
Reviewed-by: Marc-Antoine Ruel <maruel@google.com>
Commit-Queue: Oliver Newman <olivernewman@google.com>
diff --git a/scripts/tests.sh b/scripts/tests.sh
new file mode 100755
index 0000000..b9f8656
--- /dev/null
+++ b/scripts/tests.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# Copyright 2023 The Fuchsia Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+set -eu -o pipefail
+
+# TODO(olivernewman): Actually run tests once there are tests to run.
+echo "No tests run."