test program for demo

Revision:
0:333c69338ddf
diff -r 000000000000 -r 333c69338ddf mbed-os.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Mon Apr 16 09:05:50 2018 +0000
@@ -0,0 +1,1 @@
+https://github.com/armmbed/mbed-os/#f9ee4e849f8cbd64f1ec5fdd4ad256585a208360