As the connected Trezors can be left in various weird states, trezorctl
list may not always return what is expected or even fail. If it failed
TREZOR_PATH was set to empty string which means random device got
selected.
For now let's avoid using incorrect device by powering down the other
usb port.
Fix log lines ordering.
This enables to run device tests against an actual device connected to
our CI. It uses https://github.com/mmahut/tpmb to enter bootloader and
then it uploads a debug firmware to the device. The debug mode is the
used to "click" the buttons but we might improve this and actually use
the hardware buttons instead.
