Does not work with atmel atsamd21 and ST-LINK-V2

[Gabriel-Gardin]

First of all thanks for the great tool!

I was trying to flash the arduino mkr 1400 bootloader using Adalink and ST-LINK V2, but noticed it was not working. After some research found these:
https://forum.arduino.cc/index.php?topic=532385.0

In these topic other people failed to use the stlink-v2 to flash the atsamd21.

In the end I've managed to make a j-link using an stm32 and with that I correctly flashed the arduino mkr 1400 using adalink.

I dont know that this incompatibility is known by adafruit team, but I found valid to make a warn.