Show desktop notifications when tests complete.

Bug:
Change-Id: Ide0d8100c96af5190b8041d69794e4ffd1b88003
diff --git a/tools/notify.py b/tools/notify.py
new file mode 100644
index 0000000..f7ae50e
--- /dev/null
+++ b/tools/notify.py
@@ -0,0 +1,19 @@
+#!/usr/bin/env python
+# Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+try:
+  import gi
+  from gi.repository import Notify
+  Notify.init("R8 build tools")
+
+  def notify(message):
+    try:
+      Notify.Notification.new("R8 build tools", message).show()
+    except:
+      return
+
+except ImportError:
+  def notify(message):
+    return