robot-name exercise could use a test to check if the names are shuffled

[glennj]

i.e.

set r [Robot new]
set name1 [$r name]
$r reset
set name2 [$r name]
# check that name2 != name1 "+ 1"

[glennj]

Additionally, while we're here, make the last test optional: I'm getting timeouts from the test runner (although the test suite takes < 10s on my laptop)