Fixed install

libdevices_dht22/dht22

Updated to have the stub change the reported temperature every second.

README.md updates

README.md updates

README.md updates

README.md updates

README.md updatees

Added install target for program

devices/dht22.h

Fixed errors in CMakeLists where it looked for libdht22 instead of libdevices_dht22

Renamed library to libdevices_dht22.so

Added stub for dht22 so this can compile against platforms without WiringPi.

Updated ignore lists

Initial commit of libdht22 library.