Lチカ+シリアル出力

Revision:
0:c2c4a841c8f4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Wed Jan 03 07:43:46 2018 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#2b4ff78ab0a52ef1dc3f2998908453c595e2b2c0
\ No newline at end of file