The simplest program, read a single button on pin PB_4

Dependencies:   Hotboards_buttons mbed

Revision:
0:61fb1e77eaee
diff -r 000000000000 -r 61fb1e77eaee Hotboards_buttons.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Hotboards_buttons.lib	Thu Mar 03 19:50:53 2016 +0000
@@ -0,0 +1,1 @@
+https://developer.mbed.org/users/Hotboards/code/Hotboards_buttons/#810519ce94bf