Disable Raspberry Pi 3 WiFi adapter, Raspbian Jessie

This is tested and works well on 2017-07-05-raspbian-jessie-lite

At first take a look at this command:

rfkill list

This will report something like:

0: wifi: Wireless LAN
        Soft blocked: no
        Hard blocked: no
1: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no

Best way (recommended) is open:

sudo vi /boot/config.txt

and add:

dtoverlay=pi3-disable-wifi

There is other option if I do not like the first one.
I can create a configuration that prevents to load wifi driver. Here is how to do it:

vi /etc/modprobe.d/raspi-blacklist.conf

Enter content like:

#wifi
blacklist brcmfmac
blacklist brcmutil

Reboot the pi and execute again:

rfkill list

There will be wifi option available and also the tray icon do not show any wlan0 interface :)