The python2 support has been removed since the python-colorzero bump version to 2.0.
Remove the gpiozero test with python2
[1] 73bf3292e1
Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>