Example of using SD card with Mbed OS5.

Revision:
0:87642278ede6
Child:
1:9a5f06e7969e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Wed Feb 06 18:46:53 2019 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#59535b83926abb05d35f8c9b8bfbffc8a8ec25c2