list_devices() was updated to take an integer rather than a bool
for the wait_to_appear argument. This updates any tests that
explicily passed True/False as the argument to list_devices.
The single AP test worked fine, but adding a failure test caused some
problems. Since the kernel is never restarted between tests it maintains
old stale scan results from the previous test. This was causing an
assert to sometimes fail in the second test being run because it was
returning > 1 ordered networks. This change iterates through the ordered
network list and chooses the appropriate network rather than assuming
get_ordered_networks() will always return only one network object
