Added for gyro and testing

Revision:
12:6efce6d008f8
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Wed Jul 03 17:56:22 2019 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#50bd61a4a72332baa6b1bac6caccb44dc5423309