Support when multiple devices are found

#22

Thanks to @ytkg for the contribution.

Add aircon related commands.

Added the following commands to the CLI

$ natureremo aircon_off
$ natureremo aircon_on

$ natureremo aircon_change_temperature +1
$ natureremo aircon_change_temperature -1

These commands allow you to turn the air conditioner on or off and specify the relative air conditioner temperature.

Thanks to @inket for the contribution.