An ultimate I2C scanner. To be ultimate it should check speeds tbh. Arduino port really

Revision:
0:eac9f05ba8e0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Sat Jul 07 13:18:17 2018 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#35fa909641fedcad9bbe0c7300d4ccdf15a2b71a