for textbook v4.4

Dependencies:   mbed DHT11

Revision:
0:d743365e4ee4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DHT11.lib	Wed Nov 06 18:09:06 2019 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/fossum_13/code/DHT11/#5da6f6de3e42