mbed ADC read gas sensor

Revision:
0:2e74e9d97542
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Thu Oct 20 12:31:28 2016 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#a6f3fd1a60d5df59246d7caf3f108c4d34e1808e