Prints out ip address of pc in serial terminal like Tera term or Putty

Revision:
0:bbe70c857378
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Sun Mar 25 18:57:07 2018 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#16bac101a6b7b4724023dcf86ece1548e3a23cbf