Haptic feedback example for Hexiwear

Revision:
0:25305457f356
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Fri Aug 19 02:11:13 2016 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#0712b8adf6bbc7eb796d5dac26f95d79d40745ef