Task 4.2.1

Revision:
1:d8372070fc1b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Thu Jul 13 14:53:21 2017 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#8828635da469162cf2854b5287561c663fb96e72